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1c1af145 | 1 | /* |
2 | * SSH backend. | |
3 | */ | |
4 | ||
5 | #include <stdio.h> | |
6 | #include <stdlib.h> | |
7 | #include <stdarg.h> | |
8 | #include <assert.h> | |
9 | #include <limits.h> | |
10 | #include <signal.h> | |
11 | ||
12 | #include "putty.h" | |
13 | #include "tree234.h" | |
14 | #include "ssh.h" | |
15 | #ifndef NO_GSSAPI | |
16 | #include "sshgssc.h" | |
17 | #include "sshgss.h" | |
18 | #endif | |
19 | ||
20 | #ifndef FALSE | |
21 | #define FALSE 0 | |
22 | #endif | |
23 | #ifndef TRUE | |
24 | #define TRUE 1 | |
25 | #endif | |
26 | ||
27 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ | |
28 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ | |
29 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ | |
30 | #define SSH1_CMSG_USER 4 /* 0x4 */ | |
31 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ | |
32 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ | |
33 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ | |
34 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ | |
35 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ | |
36 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ | |
37 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ | |
38 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ | |
39 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ | |
40 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ | |
41 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ | |
42 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ | |
43 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ | |
44 | #define SSH1_CMSG_EOF 19 /* 0x13 */ | |
45 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ | |
46 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ | |
47 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ | |
48 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ | |
49 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ | |
50 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ | |
51 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ | |
52 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ | |
53 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ | |
54 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ | |
55 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ | |
56 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ | |
57 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ | |
58 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ | |
59 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ | |
60 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ | |
61 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ | |
62 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ | |
63 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ | |
64 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ | |
65 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ | |
66 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ | |
67 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ | |
68 | ||
69 | #define SSH1_AUTH_RHOSTS 1 /* 0x1 */ | |
70 | #define SSH1_AUTH_RSA 2 /* 0x2 */ | |
71 | #define SSH1_AUTH_PASSWORD 3 /* 0x3 */ | |
72 | #define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */ | |
73 | #define SSH1_AUTH_TIS 5 /* 0x5 */ | |
74 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ | |
75 | ||
76 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ | |
77 | /* Mask for protoflags we will echo back to server if seen */ | |
78 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ | |
79 | ||
80 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ | |
81 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ | |
82 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ | |
83 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ | |
84 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ | |
85 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ | |
86 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ | |
87 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ | |
88 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ | |
89 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ | |
90 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ | |
91 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ | |
92 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ | |
93 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ | |
94 | #define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */ | |
95 | #define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */ | |
96 | #define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */ | |
97 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ | |
98 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ | |
99 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ | |
100 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ | |
101 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ | |
102 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ | |
103 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ | |
104 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ | |
105 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ | |
106 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ | |
107 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ | |
108 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ | |
109 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ | |
110 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ | |
111 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ | |
112 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ | |
113 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ | |
114 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ | |
115 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ | |
116 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ | |
117 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ | |
118 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ | |
119 | #define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60 | |
120 | #define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61 | |
121 | #define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63 | |
122 | #define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64 | |
123 | #define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65 | |
124 | #define SSH2_MSG_USERAUTH_GSSAPI_MIC 66 | |
125 | ||
126 | /* | |
127 | * Packet type contexts, so that ssh2_pkt_type can correctly decode | |
128 | * the ambiguous type numbers back into the correct type strings. | |
129 | */ | |
130 | typedef enum { | |
131 | SSH2_PKTCTX_NOKEX, | |
132 | SSH2_PKTCTX_DHGROUP, | |
133 | SSH2_PKTCTX_DHGEX, | |
134 | SSH2_PKTCTX_RSAKEX | |
135 | } Pkt_KCtx; | |
136 | typedef enum { | |
137 | SSH2_PKTCTX_NOAUTH, | |
138 | SSH2_PKTCTX_PUBLICKEY, | |
139 | SSH2_PKTCTX_PASSWORD, | |
140 | SSH2_PKTCTX_GSSAPI, | |
141 | SSH2_PKTCTX_KBDINTER | |
142 | } Pkt_ACtx; | |
143 | ||
144 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ | |
145 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ | |
146 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ | |
147 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ | |
148 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ | |
149 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ | |
150 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ | |
151 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ | |
152 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ | |
153 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ | |
154 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ | |
155 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ | |
156 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ | |
157 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ | |
158 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ | |
159 | ||
160 | static const char *const ssh2_disconnect_reasons[] = { | |
161 | NULL, | |
162 | "host not allowed to connect", | |
163 | "protocol error", | |
164 | "key exchange failed", | |
165 | "host authentication failed", | |
166 | "MAC error", | |
167 | "compression error", | |
168 | "service not available", | |
169 | "protocol version not supported", | |
170 | "host key not verifiable", | |
171 | "connection lost", | |
172 | "by application", | |
173 | "too many connections", | |
174 | "auth cancelled by user", | |
175 | "no more auth methods available", | |
176 | "illegal user name", | |
177 | }; | |
178 | ||
179 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ | |
180 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ | |
181 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ | |
182 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ | |
183 | ||
184 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ | |
185 | ||
186 | /* | |
187 | * Various remote-bug flags. | |
188 | */ | |
189 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 | |
190 | #define BUG_SSH2_HMAC 2 | |
191 | #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 | |
192 | #define BUG_CHOKES_ON_RSA 8 | |
193 | #define BUG_SSH2_RSA_PADDING 16 | |
194 | #define BUG_SSH2_DERIVEKEY 32 | |
195 | #define BUG_SSH2_REKEY 64 | |
196 | #define BUG_SSH2_PK_SESSIONID 128 | |
197 | #define BUG_SSH2_MAXPKT 256 | |
198 | #define BUG_CHOKES_ON_SSH2_IGNORE 512 | |
199 | ||
200 | /* | |
201 | * Codes for terminal modes. | |
202 | * Most of these are the same in SSH-1 and SSH-2. | |
203 | * This list is derived from RFC 4254 and | |
204 | * SSH-1 RFC-1.2.31. | |
205 | */ | |
206 | static const struct { | |
207 | const char* const mode; | |
208 | int opcode; | |
209 | enum { TTY_OP_CHAR, TTY_OP_BOOL } type; | |
210 | } ssh_ttymodes[] = { | |
211 | /* "V" prefix discarded for special characters relative to SSH specs */ | |
212 | { "INTR", 1, TTY_OP_CHAR }, | |
213 | { "QUIT", 2, TTY_OP_CHAR }, | |
214 | { "ERASE", 3, TTY_OP_CHAR }, | |
215 | { "KILL", 4, TTY_OP_CHAR }, | |
216 | { "EOF", 5, TTY_OP_CHAR }, | |
217 | { "EOL", 6, TTY_OP_CHAR }, | |
218 | { "EOL2", 7, TTY_OP_CHAR }, | |
219 | { "START", 8, TTY_OP_CHAR }, | |
220 | { "STOP", 9, TTY_OP_CHAR }, | |
221 | { "SUSP", 10, TTY_OP_CHAR }, | |
222 | { "DSUSP", 11, TTY_OP_CHAR }, | |
223 | { "REPRINT", 12, TTY_OP_CHAR }, | |
224 | { "WERASE", 13, TTY_OP_CHAR }, | |
225 | { "LNEXT", 14, TTY_OP_CHAR }, | |
226 | { "FLUSH", 15, TTY_OP_CHAR }, | |
227 | { "SWTCH", 16, TTY_OP_CHAR }, | |
228 | { "STATUS", 17, TTY_OP_CHAR }, | |
229 | { "DISCARD", 18, TTY_OP_CHAR }, | |
230 | { "IGNPAR", 30, TTY_OP_BOOL }, | |
231 | { "PARMRK", 31, TTY_OP_BOOL }, | |
232 | { "INPCK", 32, TTY_OP_BOOL }, | |
233 | { "ISTRIP", 33, TTY_OP_BOOL }, | |
234 | { "INLCR", 34, TTY_OP_BOOL }, | |
235 | { "IGNCR", 35, TTY_OP_BOOL }, | |
236 | { "ICRNL", 36, TTY_OP_BOOL }, | |
237 | { "IUCLC", 37, TTY_OP_BOOL }, | |
238 | { "IXON", 38, TTY_OP_BOOL }, | |
239 | { "IXANY", 39, TTY_OP_BOOL }, | |
240 | { "IXOFF", 40, TTY_OP_BOOL }, | |
241 | { "IMAXBEL", 41, TTY_OP_BOOL }, | |
242 | { "ISIG", 50, TTY_OP_BOOL }, | |
243 | { "ICANON", 51, TTY_OP_BOOL }, | |
244 | { "XCASE", 52, TTY_OP_BOOL }, | |
245 | { "ECHO", 53, TTY_OP_BOOL }, | |
246 | { "ECHOE", 54, TTY_OP_BOOL }, | |
247 | { "ECHOK", 55, TTY_OP_BOOL }, | |
248 | { "ECHONL", 56, TTY_OP_BOOL }, | |
249 | { "NOFLSH", 57, TTY_OP_BOOL }, | |
250 | { "TOSTOP", 58, TTY_OP_BOOL }, | |
251 | { "IEXTEN", 59, TTY_OP_BOOL }, | |
252 | { "ECHOCTL", 60, TTY_OP_BOOL }, | |
253 | { "ECHOKE", 61, TTY_OP_BOOL }, | |
254 | { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */ | |
255 | { "OPOST", 70, TTY_OP_BOOL }, | |
256 | { "OLCUC", 71, TTY_OP_BOOL }, | |
257 | { "ONLCR", 72, TTY_OP_BOOL }, | |
258 | { "OCRNL", 73, TTY_OP_BOOL }, | |
259 | { "ONOCR", 74, TTY_OP_BOOL }, | |
260 | { "ONLRET", 75, TTY_OP_BOOL }, | |
261 | { "CS7", 90, TTY_OP_BOOL }, | |
262 | { "CS8", 91, TTY_OP_BOOL }, | |
263 | { "PARENB", 92, TTY_OP_BOOL }, | |
264 | { "PARODD", 93, TTY_OP_BOOL } | |
265 | }; | |
266 | ||
267 | /* Miscellaneous other tty-related constants. */ | |
268 | #define SSH_TTY_OP_END 0 | |
269 | /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */ | |
270 | #define SSH1_TTY_OP_ISPEED 192 | |
271 | #define SSH1_TTY_OP_OSPEED 193 | |
272 | #define SSH2_TTY_OP_ISPEED 128 | |
273 | #define SSH2_TTY_OP_OSPEED 129 | |
274 | ||
275 | /* Helper functions for parsing tty-related config. */ | |
276 | static unsigned int ssh_tty_parse_specchar(char *s) | |
277 | { | |
278 | unsigned int ret; | |
279 | if (*s) { | |
280 | char *next = NULL; | |
281 | ret = ctrlparse(s, &next); | |
282 | if (!next) ret = s[0]; | |
283 | } else { | |
284 | ret = 255; /* special value meaning "don't set" */ | |
285 | } | |
286 | return ret; | |
287 | } | |
288 | static unsigned int ssh_tty_parse_boolean(char *s) | |
289 | { | |
290 | if (stricmp(s, "yes") == 0 || | |
291 | stricmp(s, "on") == 0 || | |
292 | stricmp(s, "true") == 0 || | |
293 | stricmp(s, "+") == 0) | |
294 | return 1; /* true */ | |
295 | else if (stricmp(s, "no") == 0 || | |
296 | stricmp(s, "off") == 0 || | |
297 | stricmp(s, "false") == 0 || | |
298 | stricmp(s, "-") == 0) | |
299 | return 0; /* false */ | |
300 | else | |
301 | return (atoi(s) != 0); | |
302 | } | |
303 | ||
304 | #define translate(x) if (type == x) return #x | |
305 | #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x | |
306 | #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x | |
307 | static char *ssh1_pkt_type(int type) | |
308 | { | |
309 | translate(SSH1_MSG_DISCONNECT); | |
310 | translate(SSH1_SMSG_PUBLIC_KEY); | |
311 | translate(SSH1_CMSG_SESSION_KEY); | |
312 | translate(SSH1_CMSG_USER); | |
313 | translate(SSH1_CMSG_AUTH_RSA); | |
314 | translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); | |
315 | translate(SSH1_CMSG_AUTH_RSA_RESPONSE); | |
316 | translate(SSH1_CMSG_AUTH_PASSWORD); | |
317 | translate(SSH1_CMSG_REQUEST_PTY); | |
318 | translate(SSH1_CMSG_WINDOW_SIZE); | |
319 | translate(SSH1_CMSG_EXEC_SHELL); | |
320 | translate(SSH1_CMSG_EXEC_CMD); | |
321 | translate(SSH1_SMSG_SUCCESS); | |
322 | translate(SSH1_SMSG_FAILURE); | |
323 | translate(SSH1_CMSG_STDIN_DATA); | |
324 | translate(SSH1_SMSG_STDOUT_DATA); | |
325 | translate(SSH1_SMSG_STDERR_DATA); | |
326 | translate(SSH1_CMSG_EOF); | |
327 | translate(SSH1_SMSG_EXIT_STATUS); | |
328 | translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); | |
329 | translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); | |
330 | translate(SSH1_MSG_CHANNEL_DATA); | |
331 | translate(SSH1_MSG_CHANNEL_CLOSE); | |
332 | translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); | |
333 | translate(SSH1_SMSG_X11_OPEN); | |
334 | translate(SSH1_CMSG_PORT_FORWARD_REQUEST); | |
335 | translate(SSH1_MSG_PORT_OPEN); | |
336 | translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); | |
337 | translate(SSH1_SMSG_AGENT_OPEN); | |
338 | translate(SSH1_MSG_IGNORE); | |
339 | translate(SSH1_CMSG_EXIT_CONFIRMATION); | |
340 | translate(SSH1_CMSG_X11_REQUEST_FORWARDING); | |
341 | translate(SSH1_CMSG_AUTH_RHOSTS_RSA); | |
342 | translate(SSH1_MSG_DEBUG); | |
343 | translate(SSH1_CMSG_REQUEST_COMPRESSION); | |
344 | translate(SSH1_CMSG_AUTH_TIS); | |
345 | translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); | |
346 | translate(SSH1_CMSG_AUTH_TIS_RESPONSE); | |
347 | translate(SSH1_CMSG_AUTH_CCARD); | |
348 | translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); | |
349 | translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); | |
350 | return "unknown"; | |
351 | } | |
352 | static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) | |
353 | { | |
354 | translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI); | |
355 | translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI); | |
356 | translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI); | |
357 | translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI); | |
358 | translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI); | |
359 | translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI); | |
360 | translate(SSH2_MSG_DISCONNECT); | |
361 | translate(SSH2_MSG_IGNORE); | |
362 | translate(SSH2_MSG_UNIMPLEMENTED); | |
363 | translate(SSH2_MSG_DEBUG); | |
364 | translate(SSH2_MSG_SERVICE_REQUEST); | |
365 | translate(SSH2_MSG_SERVICE_ACCEPT); | |
366 | translate(SSH2_MSG_KEXINIT); | |
367 | translate(SSH2_MSG_NEWKEYS); | |
368 | translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP); | |
369 | translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP); | |
370 | translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); | |
371 | translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); | |
372 | translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); | |
373 | translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); | |
374 | translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX); | |
375 | translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX); | |
376 | translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX); | |
377 | translate(SSH2_MSG_USERAUTH_REQUEST); | |
378 | translate(SSH2_MSG_USERAUTH_FAILURE); | |
379 | translate(SSH2_MSG_USERAUTH_SUCCESS); | |
380 | translate(SSH2_MSG_USERAUTH_BANNER); | |
381 | translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); | |
382 | translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); | |
383 | translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); | |
384 | translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); | |
385 | translate(SSH2_MSG_GLOBAL_REQUEST); | |
386 | translate(SSH2_MSG_REQUEST_SUCCESS); | |
387 | translate(SSH2_MSG_REQUEST_FAILURE); | |
388 | translate(SSH2_MSG_CHANNEL_OPEN); | |
389 | translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
390 | translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
391 | translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
392 | translate(SSH2_MSG_CHANNEL_DATA); | |
393 | translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
394 | translate(SSH2_MSG_CHANNEL_EOF); | |
395 | translate(SSH2_MSG_CHANNEL_CLOSE); | |
396 | translate(SSH2_MSG_CHANNEL_REQUEST); | |
397 | translate(SSH2_MSG_CHANNEL_SUCCESS); | |
398 | translate(SSH2_MSG_CHANNEL_FAILURE); | |
399 | return "unknown"; | |
400 | } | |
401 | #undef translate | |
402 | #undef translatec | |
403 | ||
404 | /* Enumeration values for fields in SSH-1 packets */ | |
405 | enum { | |
406 | PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, | |
407 | /* These values are for communicating relevant semantics of | |
408 | * fields to the packet logging code. */ | |
409 | PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA | |
410 | }; | |
411 | ||
412 | /* | |
413 | * Coroutine mechanics for the sillier bits of the code. If these | |
414 | * macros look impenetrable to you, you might find it helpful to | |
415 | * read | |
416 | * | |
417 | * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html | |
418 | * | |
419 | * which explains the theory behind these macros. | |
420 | * | |
421 | * In particular, if you are getting `case expression not constant' | |
422 | * errors when building with MS Visual Studio, this is because MS's | |
423 | * Edit and Continue debugging feature causes their compiler to | |
424 | * violate ANSI C. To disable Edit and Continue debugging: | |
425 | * | |
426 | * - right-click ssh.c in the FileView | |
427 | * - click Settings | |
428 | * - select the C/C++ tab and the General category | |
429 | * - under `Debug info:', select anything _other_ than `Program | |
430 | * Database for Edit and Continue'. | |
431 | */ | |
432 | #define crBegin(v) { int *crLine = &v; switch(v) { case 0:; | |
433 | #define crState(t) \ | |
434 | struct t *s; \ | |
435 | if (!ssh->t) ssh->t = snew(struct t); \ | |
436 | s = ssh->t; | |
437 | #define crFinish(z) } *crLine = 0; return (z); } | |
438 | #define crFinishV } *crLine = 0; return; } | |
439 | #define crReturn(z) \ | |
440 | do {\ | |
441 | *crLine =__LINE__; return (z); case __LINE__:;\ | |
442 | } while (0) | |
443 | #define crReturnV \ | |
444 | do {\ | |
445 | *crLine=__LINE__; return; case __LINE__:;\ | |
446 | } while (0) | |
447 | #define crStop(z) do{ *crLine = 0; return (z); }while(0) | |
448 | #define crStopV do{ *crLine = 0; return; }while(0) | |
449 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) | |
450 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) | |
451 | ||
452 | typedef struct ssh_tag *Ssh; | |
453 | struct Packet; | |
454 | ||
455 | static struct Packet *ssh1_pkt_init(int pkt_type); | |
456 | static struct Packet *ssh2_pkt_init(int pkt_type); | |
457 | static void ssh_pkt_ensure(struct Packet *, int length); | |
458 | static void ssh_pkt_adddata(struct Packet *, void *data, int len); | |
459 | static void ssh_pkt_addbyte(struct Packet *, unsigned char value); | |
460 | static void ssh2_pkt_addbool(struct Packet *, unsigned char value); | |
461 | static void ssh_pkt_adduint32(struct Packet *, unsigned long value); | |
462 | static void ssh_pkt_addstring_start(struct Packet *); | |
463 | static void ssh_pkt_addstring_str(struct Packet *, char *data); | |
464 | static void ssh_pkt_addstring_data(struct Packet *, char *data, int len); | |
465 | static void ssh_pkt_addstring(struct Packet *, char *data); | |
466 | static unsigned char *ssh2_mpint_fmt(Bignum b, int *len); | |
467 | static void ssh1_pkt_addmp(struct Packet *, Bignum b); | |
468 | static void ssh2_pkt_addmp(struct Packet *, Bignum b); | |
469 | static int ssh2_pkt_construct(Ssh, struct Packet *); | |
470 | static void ssh2_pkt_send(Ssh, struct Packet *); | |
471 | static void ssh2_pkt_send_noqueue(Ssh, struct Packet *); | |
472 | static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, | |
473 | struct Packet *pktin); | |
474 | static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, | |
475 | struct Packet *pktin); | |
476 | ||
477 | /* | |
478 | * Buffer management constants. There are several of these for | |
479 | * various different purposes: | |
480 | * | |
481 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up | |
482 | * on a local data stream before we throttle the whole SSH | |
483 | * connection (in SSH-1 only). Throttling the whole connection is | |
484 | * pretty drastic so we set this high in the hope it won't | |
485 | * happen very often. | |
486 | * | |
487 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up | |
488 | * on the SSH connection itself before we defensively throttle | |
489 | * _all_ local data streams. This is pretty drastic too (though | |
490 | * thankfully unlikely in SSH-2 since the window mechanism should | |
491 | * ensure that the server never has any need to throttle its end | |
492 | * of the connection), so we set this high as well. | |
493 | * | |
494 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 | |
495 | * channels. | |
496 | * | |
497 | * - OUR_V2_BIGWIN is the window size we advertise for the only | |
498 | * channel in a simple connection. It must be <= INT_MAX. | |
499 | * | |
500 | * - OUR_V2_MAXPKT is the official "maximum packet size" we send | |
501 | * to the remote side. This actually has nothing to do with the | |
502 | * size of the _packet_, but is instead a limit on the amount | |
503 | * of data we're willing to receive in a single SSH2 channel | |
504 | * data message. | |
505 | * | |
506 | * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH | |
507 | * _packet_ we're prepared to cope with. It must be a multiple | |
508 | * of the cipher block size, and must be at least 35000. | |
509 | */ | |
510 | ||
511 | #define SSH1_BUFFER_LIMIT 32768 | |
512 | #define SSH_MAX_BACKLOG 32768 | |
513 | #define OUR_V2_WINSIZE 16384 | |
514 | #define OUR_V2_BIGWIN 0x7fffffff | |
515 | #define OUR_V2_MAXPKT 0x4000UL | |
516 | #define OUR_V2_PACKETLIMIT 0x9000UL | |
517 | ||
518 | /* Maximum length of passwords/passphrases (arbitrary) */ | |
519 | #define SSH_MAX_PASSWORD_LEN 100 | |
520 | ||
521 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; | |
522 | ||
523 | const static struct ssh_mac *macs[] = { | |
524 | &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 | |
525 | }; | |
526 | const static struct ssh_mac *buggymacs[] = { | |
527 | &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5 | |
528 | }; | |
529 | ||
530 | static void *ssh_comp_none_init(void) | |
531 | { | |
532 | return NULL; | |
533 | } | |
534 | static void ssh_comp_none_cleanup(void *handle) | |
535 | { | |
536 | } | |
537 | static int ssh_comp_none_block(void *handle, unsigned char *block, int len, | |
538 | unsigned char **outblock, int *outlen) | |
539 | { | |
540 | return 0; | |
541 | } | |
542 | static int ssh_comp_none_disable(void *handle) | |
543 | { | |
544 | return 0; | |
545 | } | |
546 | const static struct ssh_compress ssh_comp_none = { | |
547 | "none", NULL, | |
548 | ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, | |
549 | ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, | |
550 | ssh_comp_none_disable, NULL | |
551 | }; | |
552 | extern const struct ssh_compress ssh_zlib; | |
553 | const static struct ssh_compress *compressions[] = { | |
554 | &ssh_zlib, &ssh_comp_none | |
555 | }; | |
556 | ||
557 | enum { /* channel types */ | |
558 | CHAN_MAINSESSION, | |
559 | CHAN_X11, | |
560 | CHAN_AGENT, | |
561 | CHAN_SOCKDATA, | |
562 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ | |
563 | }; | |
564 | ||
565 | /* | |
566 | * little structure to keep track of outstanding WINDOW_ADJUSTs | |
567 | */ | |
568 | struct winadj { | |
569 | struct winadj *next; | |
570 | unsigned size; | |
571 | }; | |
572 | ||
573 | /* | |
574 | * 2-3-4 tree storing channels. | |
575 | */ | |
576 | struct ssh_channel { | |
577 | Ssh ssh; /* pointer back to main context */ | |
578 | unsigned remoteid, localid; | |
579 | int type; | |
580 | /* True if we opened this channel but server hasn't confirmed. */ | |
581 | int halfopen; | |
582 | /* | |
583 | * In SSH-1, this value contains four bits: | |
584 | * | |
585 | * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. | |
586 | * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. | |
587 | * 4 We have received SSH1_MSG_CHANNEL_CLOSE. | |
588 | * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. | |
589 | * | |
590 | * A channel is completely finished with when all four bits are set. | |
591 | */ | |
592 | int closes; | |
593 | ||
594 | /* | |
595 | * This flag indicates that a close is pending on the outgoing | |
596 | * side of the channel: that is, wherever we're getting the data | |
597 | * for this channel has sent us some data followed by EOF. We | |
598 | * can't actually close the channel until we've finished sending | |
599 | * the data, so we set this flag instead to remind us to | |
600 | * initiate the closing process once our buffer is clear. | |
601 | */ | |
602 | int pending_close; | |
603 | ||
604 | /* | |
605 | * True if this channel is causing the underlying connection to be | |
606 | * throttled. | |
607 | */ | |
608 | int throttling_conn; | |
609 | union { | |
610 | struct ssh2_data_channel { | |
611 | bufchain outbuffer; | |
612 | unsigned remwindow, remmaxpkt; | |
613 | /* locwindow is signed so we can cope with excess data. */ | |
614 | int locwindow, locmaxwin; | |
615 | /* | |
616 | * remlocwin is the amount of local window that we think | |
617 | * the remote end had available to it after it sent the | |
618 | * last data packet or window adjust ack. | |
619 | */ | |
620 | int remlocwin; | |
621 | /* | |
622 | * These store the list of window adjusts that haven't | |
623 | * been acked. | |
624 | */ | |
625 | struct winadj *winadj_head, *winadj_tail; | |
626 | enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state; | |
627 | } v2; | |
628 | } v; | |
629 | union { | |
630 | struct ssh_agent_channel { | |
631 | unsigned char *message; | |
632 | unsigned char msglen[4]; | |
633 | unsigned lensofar, totallen; | |
634 | } a; | |
635 | struct ssh_x11_channel { | |
636 | Socket s; | |
637 | } x11; | |
638 | struct ssh_pfd_channel { | |
639 | Socket s; | |
640 | } pfd; | |
641 | } u; | |
642 | }; | |
643 | ||
644 | /* | |
645 | * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2 | |
646 | * use this structure in different ways, reflecting SSH-2's | |
647 | * altogether saner approach to port forwarding. | |
648 | * | |
649 | * In SSH-1, you arrange a remote forwarding by sending the server | |
650 | * the remote port number, and the local destination host:port. | |
651 | * When a connection comes in, the server sends you back that | |
652 | * host:port pair, and you connect to it. This is a ready-made | |
653 | * security hole if you're not on the ball: a malicious server | |
654 | * could send you back _any_ host:port pair, so if you trustingly | |
655 | * connect to the address it gives you then you've just opened the | |
656 | * entire inside of your corporate network just by connecting | |
657 | * through it to a dodgy SSH server. Hence, we must store a list of | |
658 | * host:port pairs we _are_ trying to forward to, and reject a | |
659 | * connection request from the server if it's not in the list. | |
660 | * | |
661 | * In SSH-2, each side of the connection minds its own business and | |
662 | * doesn't send unnecessary information to the other. You arrange a | |
663 | * remote forwarding by sending the server just the remote port | |
664 | * number. When a connection comes in, the server tells you which | |
665 | * of its ports was connected to; and _you_ have to remember what | |
666 | * local host:port pair went with that port number. | |
667 | * | |
668 | * Hence, in SSH-1 this structure is indexed by destination | |
669 | * host:port pair, whereas in SSH-2 it is indexed by source port. | |
670 | */ | |
671 | struct ssh_portfwd; /* forward declaration */ | |
672 | ||
673 | struct ssh_rportfwd { | |
674 | unsigned sport, dport; | |
675 | char dhost[256]; | |
676 | char *sportdesc; | |
677 | struct ssh_portfwd *pfrec; | |
678 | }; | |
679 | #define free_rportfwd(pf) ( \ | |
680 | ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) ) | |
681 | ||
682 | /* | |
683 | * Separately to the rportfwd tree (which is for looking up port | |
684 | * open requests from the server), a tree of _these_ structures is | |
685 | * used to keep track of all the currently open port forwardings, | |
686 | * so that we can reconfigure in mid-session if the user requests | |
687 | * it. | |
688 | */ | |
689 | struct ssh_portfwd { | |
690 | enum { DESTROY, KEEP, CREATE } status; | |
691 | int type; | |
692 | unsigned sport, dport; | |
693 | char *saddr, *daddr; | |
694 | char *sserv, *dserv; | |
695 | struct ssh_rportfwd *remote; | |
696 | int addressfamily; | |
697 | void *local; | |
698 | }; | |
699 | #define free_portfwd(pf) ( \ | |
700 | ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \ | |
701 | sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) ) | |
702 | ||
703 | struct Packet { | |
704 | long length; /* length of `data' actually used */ | |
705 | long forcepad; /* SSH-2: force padding to at least this length */ | |
706 | int type; /* only used for incoming packets */ | |
707 | unsigned long sequence; /* SSH-2 incoming sequence number */ | |
708 | unsigned char *data; /* allocated storage */ | |
709 | unsigned char *body; /* offset of payload within `data' */ | |
710 | long savedpos; /* temporary index into `data' (for strings) */ | |
711 | long maxlen; /* amount of storage allocated for `data' */ | |
712 | long encrypted_len; /* for SSH-2 total-size counting */ | |
713 | ||
714 | /* | |
715 | * State associated with packet logging | |
716 | */ | |
717 | int logmode; | |
718 | int nblanks; | |
719 | struct logblank_t *blanks; | |
720 | }; | |
721 | ||
722 | static void ssh1_protocol(Ssh ssh, void *vin, int inlen, | |
723 | struct Packet *pktin); | |
724 | static void ssh2_protocol(Ssh ssh, void *vin, int inlen, | |
725 | struct Packet *pktin); | |
726 | static void ssh1_protocol_setup(Ssh ssh); | |
727 | static void ssh2_protocol_setup(Ssh ssh); | |
728 | static void ssh_size(void *handle, int width, int height); | |
729 | static void ssh_special(void *handle, Telnet_Special); | |
730 | static int ssh2_try_send(struct ssh_channel *c); | |
731 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); | |
732 | static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); | |
733 | static void ssh2_set_window(struct ssh_channel *c, int newwin); | |
734 | static int ssh_sendbuffer(void *handle); | |
735 | static int ssh_do_close(Ssh ssh, int notify_exit); | |
736 | static unsigned long ssh_pkt_getuint32(struct Packet *pkt); | |
737 | static int ssh2_pkt_getbool(struct Packet *pkt); | |
738 | static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length); | |
739 | static void ssh2_timer(void *ctx, long now); | |
740 | static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, | |
741 | struct Packet *pktin); | |
742 | ||
743 | struct rdpkt1_state_tag { | |
744 | long len, pad, biglen, to_read; | |
745 | unsigned long realcrc, gotcrc; | |
746 | unsigned char *p; | |
747 | int i; | |
748 | int chunk; | |
749 | struct Packet *pktin; | |
750 | }; | |
751 | ||
752 | struct rdpkt2_state_tag { | |
753 | long len, pad, payload, packetlen, maclen; | |
754 | int i; | |
755 | int cipherblk; | |
756 | unsigned long incoming_sequence; | |
757 | struct Packet *pktin; | |
758 | }; | |
759 | ||
760 | typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin); | |
761 | typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx); | |
762 | ||
763 | struct queued_handler; | |
764 | struct queued_handler { | |
765 | int msg1, msg2; | |
766 | chandler_fn_t handler; | |
767 | void *ctx; | |
768 | struct queued_handler *next; | |
769 | }; | |
770 | ||
771 | struct ssh_tag { | |
772 | const struct plug_function_table *fn; | |
773 | /* the above field _must_ be first in the structure */ | |
774 | ||
775 | char *v_c, *v_s; | |
776 | void *exhash; | |
777 | ||
778 | Socket s; | |
779 | ||
780 | void *ldisc; | |
781 | void *logctx; | |
782 | ||
783 | unsigned char session_key[32]; | |
784 | int v1_compressing; | |
785 | int v1_remote_protoflags; | |
786 | int v1_local_protoflags; | |
787 | int agentfwd_enabled; | |
788 | int X11_fwd_enabled; | |
789 | int remote_bugs; | |
790 | const struct ssh_cipher *cipher; | |
791 | void *v1_cipher_ctx; | |
792 | void *crcda_ctx; | |
793 | const struct ssh2_cipher *cscipher, *sccipher; | |
794 | void *cs_cipher_ctx, *sc_cipher_ctx; | |
795 | const struct ssh_mac *csmac, *scmac; | |
796 | void *cs_mac_ctx, *sc_mac_ctx; | |
797 | const struct ssh_compress *cscomp, *sccomp; | |
798 | void *cs_comp_ctx, *sc_comp_ctx; | |
799 | const struct ssh_kex *kex; | |
800 | const struct ssh_signkey *hostkey; | |
801 | unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN]; | |
802 | int v2_session_id_len; | |
803 | void *kex_ctx; | |
804 | ||
805 | char *savedhost; | |
806 | int savedport; | |
807 | int send_ok; | |
808 | int echoing, editing; | |
809 | ||
810 | void *frontend; | |
811 | ||
812 | int ospeed, ispeed; /* temporaries */ | |
813 | int term_width, term_height; | |
814 | ||
815 | tree234 *channels; /* indexed by local id */ | |
816 | struct ssh_channel *mainchan; /* primary session channel */ | |
817 | int ncmode; /* is primary channel direct-tcpip? */ | |
818 | int exitcode; | |
819 | int close_expected; | |
820 | int clean_exit; | |
821 | ||
822 | tree234 *rportfwds, *portfwds; | |
823 | ||
824 | enum { | |
825 | SSH_STATE_PREPACKET, | |
826 | SSH_STATE_BEFORE_SIZE, | |
827 | SSH_STATE_INTERMED, | |
828 | SSH_STATE_SESSION, | |
829 | SSH_STATE_CLOSED | |
830 | } state; | |
831 | ||
832 | int size_needed, eof_needed; | |
833 | ||
834 | struct Packet **queue; | |
835 | int queuelen, queuesize; | |
836 | int queueing; | |
837 | unsigned char *deferred_send_data; | |
838 | int deferred_len, deferred_size; | |
839 | ||
840 | /* | |
841 | * Gross hack: pscp will try to start SFTP but fall back to | |
842 | * scp1 if that fails. This variable is the means by which | |
843 | * scp.c can reach into the SSH code and find out which one it | |
844 | * got. | |
845 | */ | |
846 | int fallback_cmd; | |
847 | ||
848 | bufchain banner; /* accumulates banners during do_ssh2_authconn */ | |
849 | ||
850 | Pkt_KCtx pkt_kctx; | |
851 | Pkt_ACtx pkt_actx; | |
852 | ||
853 | struct X11Display *x11disp; | |
854 | ||
855 | int version; | |
856 | int conn_throttle_count; | |
857 | int overall_bufsize; | |
858 | int throttled_all; | |
859 | int v1_stdout_throttling; | |
860 | unsigned long v2_outgoing_sequence; | |
861 | ||
862 | int ssh1_rdpkt_crstate; | |
863 | int ssh2_rdpkt_crstate; | |
864 | int do_ssh_init_crstate; | |
865 | int ssh_gotdata_crstate; | |
866 | int do_ssh1_login_crstate; | |
867 | int do_ssh1_connection_crstate; | |
868 | int do_ssh2_transport_crstate; | |
869 | int do_ssh2_authconn_crstate; | |
870 | ||
871 | void *do_ssh_init_state; | |
872 | void *do_ssh1_login_state; | |
873 | void *do_ssh2_transport_state; | |
874 | void *do_ssh2_authconn_state; | |
875 | ||
876 | struct rdpkt1_state_tag rdpkt1_state; | |
877 | struct rdpkt2_state_tag rdpkt2_state; | |
878 | ||
879 | /* SSH-1 and SSH-2 use this for different things, but both use it */ | |
880 | int protocol_initial_phase_done; | |
881 | ||
882 | void (*protocol) (Ssh ssh, void *vin, int inlen, | |
883 | struct Packet *pkt); | |
884 | struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); | |
885 | ||
886 | /* | |
887 | * We maintain a full _copy_ of a Config structure here, not | |
888 | * merely a pointer to it. That way, when we're passed a new | |
889 | * one for reconfiguration, we can check the differences and | |
890 | * potentially reconfigure port forwardings etc in mid-session. | |
891 | */ | |
892 | Config cfg; | |
893 | ||
894 | /* | |
895 | * Used to transfer data back from async callbacks. | |
896 | */ | |
897 | void *agent_response; | |
898 | int agent_response_len; | |
899 | int user_response; | |
900 | ||
901 | /* | |
902 | * The SSH connection can be set as `frozen', meaning we are | |
903 | * not currently accepting incoming data from the network. This | |
904 | * is slightly more serious than setting the _socket_ as | |
905 | * frozen, because we may already have had data passed to us | |
906 | * from the network which we need to delay processing until | |
907 | * after the freeze is lifted, so we also need a bufchain to | |
908 | * store that data. | |
909 | */ | |
910 | int frozen; | |
911 | bufchain queued_incoming_data; | |
912 | ||
913 | /* | |
914 | * Dispatch table for packet types that we may have to deal | |
915 | * with at any time. | |
916 | */ | |
917 | handler_fn_t packet_dispatch[256]; | |
918 | ||
919 | /* | |
920 | * Queues of one-off handler functions for success/failure | |
921 | * indications from a request. | |
922 | */ | |
923 | struct queued_handler *qhead, *qtail; | |
924 | ||
925 | /* | |
926 | * This module deals with sending keepalives. | |
927 | */ | |
928 | Pinger pinger; | |
929 | ||
930 | /* | |
931 | * Track incoming and outgoing data sizes and time, for | |
932 | * size-based rekeys. | |
933 | */ | |
934 | unsigned long incoming_data_size, outgoing_data_size, deferred_data_size; | |
935 | unsigned long max_data_size; | |
936 | int kex_in_progress; | |
937 | long next_rekey, last_rekey; | |
938 | char *deferred_rekey_reason; /* points to STATIC string; don't free */ | |
939 | ||
940 | /* | |
941 | * Fully qualified host name, which we need if doing GSSAPI. | |
942 | */ | |
943 | char *fullhostname; | |
944 | ||
945 | #ifndef NO_GSSAPI | |
946 | /* | |
947 | * GSSAPI libraries for this session. | |
948 | */ | |
949 | struct ssh_gss_liblist *gsslibs; | |
950 | #endif | |
951 | }; | |
952 | ||
953 | #define logevent(s) logevent(ssh->frontend, s) | |
954 | ||
955 | /* logevent, only printf-formatted. */ | |
956 | static void logeventf(Ssh ssh, const char *fmt, ...) | |
957 | { | |
958 | va_list ap; | |
959 | char *buf; | |
960 | ||
961 | va_start(ap, fmt); | |
962 | buf = dupvprintf(fmt, ap); | |
963 | va_end(ap); | |
964 | logevent(buf); | |
965 | sfree(buf); | |
966 | } | |
967 | ||
968 | #define bombout(msg) \ | |
969 | do { \ | |
970 | char *text = dupprintf msg; \ | |
971 | ssh_do_close(ssh, FALSE); \ | |
972 | logevent(text); \ | |
973 | connection_fatal(ssh->frontend, "%s", text); \ | |
974 | sfree(text); \ | |
975 | } while (0) | |
976 | ||
977 | /* Functions to leave bits out of the SSH packet log file. */ | |
978 | ||
979 | static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype) | |
980 | { | |
981 | if (ssh->cfg.logomitpass) | |
982 | pkt->logmode = blanktype; | |
983 | } | |
984 | ||
985 | static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype) | |
986 | { | |
987 | if (ssh->cfg.logomitdata) | |
988 | pkt->logmode = blanktype; | |
989 | } | |
990 | ||
991 | static void end_log_omission(Ssh ssh, struct Packet *pkt) | |
992 | { | |
993 | pkt->logmode = PKTLOG_EMIT; | |
994 | } | |
995 | ||
996 | /* Helper function for common bits of parsing cfg.ttymodes. */ | |
997 | static void parse_ttymodes(Ssh ssh, char *modes, | |
998 | void (*do_mode)(void *data, char *mode, char *val), | |
999 | void *data) | |
1000 | { | |
1001 | while (*modes) { | |
1002 | char *t = strchr(modes, '\t'); | |
1003 | char *m = snewn(t-modes+1, char); | |
1004 | char *val; | |
1005 | strncpy(m, modes, t-modes); | |
1006 | m[t-modes] = '\0'; | |
1007 | if (*(t+1) == 'A') | |
1008 | val = get_ttymode(ssh->frontend, m); | |
1009 | else | |
1010 | val = dupstr(t+2); | |
1011 | if (val) | |
1012 | do_mode(data, m, val); | |
1013 | sfree(m); | |
1014 | sfree(val); | |
1015 | modes += strlen(modes) + 1; | |
1016 | } | |
1017 | } | |
1018 | ||
1019 | static int ssh_channelcmp(void *av, void *bv) | |
1020 | { | |
1021 | struct ssh_channel *a = (struct ssh_channel *) av; | |
1022 | struct ssh_channel *b = (struct ssh_channel *) bv; | |
1023 | if (a->localid < b->localid) | |
1024 | return -1; | |
1025 | if (a->localid > b->localid) | |
1026 | return +1; | |
1027 | return 0; | |
1028 | } | |
1029 | static int ssh_channelfind(void *av, void *bv) | |
1030 | { | |
1031 | unsigned *a = (unsigned *) av; | |
1032 | struct ssh_channel *b = (struct ssh_channel *) bv; | |
1033 | if (*a < b->localid) | |
1034 | return -1; | |
1035 | if (*a > b->localid) | |
1036 | return +1; | |
1037 | return 0; | |
1038 | } | |
1039 | ||
1040 | static int ssh_rportcmp_ssh1(void *av, void *bv) | |
1041 | { | |
1042 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; | |
1043 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; | |
1044 | int i; | |
1045 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) | |
1046 | return i < 0 ? -1 : +1; | |
1047 | if (a->dport > b->dport) | |
1048 | return +1; | |
1049 | if (a->dport < b->dport) | |
1050 | return -1; | |
1051 | return 0; | |
1052 | } | |
1053 | ||
1054 | static int ssh_rportcmp_ssh2(void *av, void *bv) | |
1055 | { | |
1056 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; | |
1057 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; | |
1058 | ||
1059 | if (a->sport > b->sport) | |
1060 | return +1; | |
1061 | if (a->sport < b->sport) | |
1062 | return -1; | |
1063 | return 0; | |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * Special form of strcmp which can cope with NULL inputs. NULL is | |
1068 | * defined to sort before even the empty string. | |
1069 | */ | |
1070 | static int nullstrcmp(const char *a, const char *b) | |
1071 | { | |
1072 | if (a == NULL && b == NULL) | |
1073 | return 0; | |
1074 | if (a == NULL) | |
1075 | return -1; | |
1076 | if (b == NULL) | |
1077 | return +1; | |
1078 | return strcmp(a, b); | |
1079 | } | |
1080 | ||
1081 | static int ssh_portcmp(void *av, void *bv) | |
1082 | { | |
1083 | struct ssh_portfwd *a = (struct ssh_portfwd *) av; | |
1084 | struct ssh_portfwd *b = (struct ssh_portfwd *) bv; | |
1085 | int i; | |
1086 | if (a->type > b->type) | |
1087 | return +1; | |
1088 | if (a->type < b->type) | |
1089 | return -1; | |
1090 | if (a->addressfamily > b->addressfamily) | |
1091 | return +1; | |
1092 | if (a->addressfamily < b->addressfamily) | |
1093 | return -1; | |
1094 | if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0) | |
1095 | return i < 0 ? -1 : +1; | |
1096 | if (a->sport > b->sport) | |
1097 | return +1; | |
1098 | if (a->sport < b->sport) | |
1099 | return -1; | |
1100 | if (a->type != 'D') { | |
1101 | if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0) | |
1102 | return i < 0 ? -1 : +1; | |
1103 | if (a->dport > b->dport) | |
1104 | return +1; | |
1105 | if (a->dport < b->dport) | |
1106 | return -1; | |
1107 | } | |
1108 | return 0; | |
1109 | } | |
1110 | ||
1111 | static int alloc_channel_id(Ssh ssh) | |
1112 | { | |
1113 | const unsigned CHANNEL_NUMBER_OFFSET = 256; | |
1114 | unsigned low, high, mid; | |
1115 | int tsize; | |
1116 | struct ssh_channel *c; | |
1117 | ||
1118 | /* | |
1119 | * First-fit allocation of channel numbers: always pick the | |
1120 | * lowest unused one. To do this, binary-search using the | |
1121 | * counted B-tree to find the largest channel ID which is in a | |
1122 | * contiguous sequence from the beginning. (Precisely | |
1123 | * everything in that sequence must have ID equal to its tree | |
1124 | * index plus CHANNEL_NUMBER_OFFSET.) | |
1125 | */ | |
1126 | tsize = count234(ssh->channels); | |
1127 | ||
1128 | low = -1; | |
1129 | high = tsize; | |
1130 | while (high - low > 1) { | |
1131 | mid = (high + low) / 2; | |
1132 | c = index234(ssh->channels, mid); | |
1133 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) | |
1134 | low = mid; /* this one is fine */ | |
1135 | else | |
1136 | high = mid; /* this one is past it */ | |
1137 | } | |
1138 | /* | |
1139 | * Now low points to either -1, or the tree index of the | |
1140 | * largest ID in the initial sequence. | |
1141 | */ | |
1142 | { | |
1143 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; | |
1144 | assert(NULL == find234(ssh->channels, &i, ssh_channelfind)); | |
1145 | } | |
1146 | return low + 1 + CHANNEL_NUMBER_OFFSET; | |
1147 | } | |
1148 | ||
1149 | static void c_write_stderr(int trusted, const char *buf, int len) | |
1150 | { | |
1151 | int i; | |
1152 | for (i = 0; i < len; i++) | |
1153 | if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60))) | |
1154 | fputc(buf[i], stderr); | |
1155 | } | |
1156 | ||
1157 | static void c_write(Ssh ssh, const char *buf, int len) | |
1158 | { | |
1159 | if (flags & FLAG_STDERR) | |
1160 | c_write_stderr(1, buf, len); | |
1161 | else | |
1162 | from_backend(ssh->frontend, 1, buf, len); | |
1163 | } | |
1164 | ||
1165 | static void c_write_untrusted(Ssh ssh, const char *buf, int len) | |
1166 | { | |
1167 | if (flags & FLAG_STDERR) | |
1168 | c_write_stderr(0, buf, len); | |
1169 | else | |
1170 | from_backend_untrusted(ssh->frontend, buf, len); | |
1171 | } | |
1172 | ||
1173 | static void c_write_str(Ssh ssh, const char *buf) | |
1174 | { | |
1175 | c_write(ssh, buf, strlen(buf)); | |
1176 | } | |
1177 | ||
1178 | static void ssh_free_packet(struct Packet *pkt) | |
1179 | { | |
1180 | sfree(pkt->data); | |
1181 | sfree(pkt); | |
1182 | } | |
1183 | static struct Packet *ssh_new_packet(void) | |
1184 | { | |
1185 | struct Packet *pkt = snew(struct Packet); | |
1186 | ||
1187 | pkt->body = pkt->data = NULL; | |
1188 | pkt->maxlen = 0; | |
1189 | pkt->logmode = PKTLOG_EMIT; | |
1190 | pkt->nblanks = 0; | |
1191 | pkt->blanks = NULL; | |
1192 | ||
1193 | return pkt; | |
1194 | } | |
1195 | ||
1196 | /* | |
1197 | * Collect incoming data in the incoming packet buffer. | |
1198 | * Decipher and verify the packet when it is completely read. | |
1199 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. | |
1200 | * Update the *data and *datalen variables. | |
1201 | * Return a Packet structure when a packet is completed. | |
1202 | */ | |
1203 | static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) | |
1204 | { | |
1205 | struct rdpkt1_state_tag *st = &ssh->rdpkt1_state; | |
1206 | ||
1207 | crBegin(ssh->ssh1_rdpkt_crstate); | |
1208 | ||
1209 | st->pktin = ssh_new_packet(); | |
1210 | ||
1211 | st->pktin->type = 0; | |
1212 | st->pktin->length = 0; | |
1213 | ||
1214 | for (st->i = st->len = 0; st->i < 4; st->i++) { | |
1215 | while ((*datalen) == 0) | |
1216 | crReturn(NULL); | |
1217 | st->len = (st->len << 8) + **data; | |
1218 | (*data)++, (*datalen)--; | |
1219 | } | |
1220 | ||
1221 | st->pad = 8 - (st->len % 8); | |
1222 | st->biglen = st->len + st->pad; | |
1223 | st->pktin->length = st->len - 5; | |
1224 | ||
1225 | if (st->biglen < 0) { | |
1226 | bombout(("Extremely large packet length from server suggests" | |
1227 | " data stream corruption")); | |
1228 | ssh_free_packet(st->pktin); | |
1229 | crStop(NULL); | |
1230 | } | |
1231 | ||
1232 | st->pktin->maxlen = st->biglen; | |
1233 | st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char); | |
1234 | ||
1235 | st->to_read = st->biglen; | |
1236 | st->p = st->pktin->data; | |
1237 | while (st->to_read > 0) { | |
1238 | st->chunk = st->to_read; | |
1239 | while ((*datalen) == 0) | |
1240 | crReturn(NULL); | |
1241 | if (st->chunk > (*datalen)) | |
1242 | st->chunk = (*datalen); | |
1243 | memcpy(st->p, *data, st->chunk); | |
1244 | *data += st->chunk; | |
1245 | *datalen -= st->chunk; | |
1246 | st->p += st->chunk; | |
1247 | st->to_read -= st->chunk; | |
1248 | } | |
1249 | ||
1250 | if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data, | |
1251 | st->biglen, NULL)) { | |
1252 | bombout(("Network attack (CRC compensation) detected!")); | |
1253 | ssh_free_packet(st->pktin); | |
1254 | crStop(NULL); | |
1255 | } | |
1256 | ||
1257 | if (ssh->cipher) | |
1258 | ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen); | |
1259 | ||
1260 | st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4); | |
1261 | st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4); | |
1262 | if (st->gotcrc != st->realcrc) { | |
1263 | bombout(("Incorrect CRC received on packet")); | |
1264 | ssh_free_packet(st->pktin); | |
1265 | crStop(NULL); | |
1266 | } | |
1267 | ||
1268 | st->pktin->body = st->pktin->data + st->pad + 1; | |
1269 | st->pktin->savedpos = 0; | |
1270 | ||
1271 | if (ssh->v1_compressing) { | |
1272 | unsigned char *decompblk; | |
1273 | int decomplen; | |
1274 | if (!zlib_decompress_block(ssh->sc_comp_ctx, | |
1275 | st->pktin->body - 1, st->pktin->length + 1, | |
1276 | &decompblk, &decomplen)) { | |
1277 | bombout(("Zlib decompression encountered invalid data")); | |
1278 | ssh_free_packet(st->pktin); | |
1279 | crStop(NULL); | |
1280 | } | |
1281 | ||
1282 | if (st->pktin->maxlen < st->pad + decomplen) { | |
1283 | st->pktin->maxlen = st->pad + decomplen; | |
1284 | st->pktin->data = sresize(st->pktin->data, | |
1285 | st->pktin->maxlen + APIEXTRA, | |
1286 | unsigned char); | |
1287 | st->pktin->body = st->pktin->data + st->pad + 1; | |
1288 | } | |
1289 | ||
1290 | memcpy(st->pktin->body - 1, decompblk, decomplen); | |
1291 | sfree(decompblk); | |
1292 | st->pktin->length = decomplen - 1; | |
1293 | } | |
1294 | ||
1295 | st->pktin->type = st->pktin->body[-1]; | |
1296 | ||
1297 | /* | |
1298 | * Log incoming packet, possibly omitting sensitive fields. | |
1299 | */ | |
1300 | if (ssh->logctx) { | |
1301 | int nblanks = 0; | |
1302 | struct logblank_t blank; | |
1303 | if (ssh->cfg.logomitdata) { | |
1304 | int do_blank = FALSE, blank_prefix = 0; | |
1305 | /* "Session data" packets - omit the data field */ | |
1306 | if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) || | |
1307 | (st->pktin->type == SSH1_SMSG_STDERR_DATA)) { | |
1308 | do_blank = TRUE; blank_prefix = 4; | |
1309 | } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) { | |
1310 | do_blank = TRUE; blank_prefix = 8; | |
1311 | } | |
1312 | if (do_blank) { | |
1313 | blank.offset = blank_prefix; | |
1314 | blank.len = st->pktin->length; | |
1315 | blank.type = PKTLOG_OMIT; | |
1316 | nblanks = 1; | |
1317 | } | |
1318 | } | |
1319 | log_packet(ssh->logctx, | |
1320 | PKT_INCOMING, st->pktin->type, | |
1321 | ssh1_pkt_type(st->pktin->type), | |
1322 | st->pktin->body, st->pktin->length, | |
1323 | nblanks, &blank, NULL); | |
1324 | } | |
1325 | ||
1326 | crFinish(st->pktin); | |
1327 | } | |
1328 | ||
1329 | static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) | |
1330 | { | |
1331 | struct rdpkt2_state_tag *st = &ssh->rdpkt2_state; | |
1332 | ||
1333 | crBegin(ssh->ssh2_rdpkt_crstate); | |
1334 | ||
1335 | st->pktin = ssh_new_packet(); | |
1336 | ||
1337 | st->pktin->type = 0; | |
1338 | st->pktin->length = 0; | |
1339 | if (ssh->sccipher) | |
1340 | st->cipherblk = ssh->sccipher->blksize; | |
1341 | else | |
1342 | st->cipherblk = 8; | |
1343 | if (st->cipherblk < 8) | |
1344 | st->cipherblk = 8; | |
1345 | st->maclen = ssh->scmac ? ssh->scmac->len : 0; | |
1346 | ||
1347 | if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) && | |
1348 | ssh->scmac) { | |
1349 | /* | |
1350 | * When dealing with a CBC-mode cipher, we want to avoid the | |
1351 | * possibility of an attacker's tweaking the ciphertext stream | |
1352 | * so as to cause us to feed the same block to the block | |
1353 | * cipher more than once and thus leak information | |
1354 | * (VU#958563). The way we do this is not to take any | |
1355 | * decisions on the basis of anything we've decrypted until | |
1356 | * we've verified it with a MAC. That includes the packet | |
1357 | * length, so we just read data and check the MAC repeatedly, | |
1358 | * and when the MAC passes, see if the length we've got is | |
1359 | * plausible. | |
1360 | */ | |
1361 | ||
1362 | /* May as well allocate the whole lot now. */ | |
1363 | st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA, | |
1364 | unsigned char); | |
1365 | ||
1366 | /* Read an amount corresponding to the MAC. */ | |
1367 | for (st->i = 0; st->i < st->maclen; st->i++) { | |
1368 | while ((*datalen) == 0) | |
1369 | crReturn(NULL); | |
1370 | st->pktin->data[st->i] = *(*data)++; | |
1371 | (*datalen)--; | |
1372 | } | |
1373 | ||
1374 | st->packetlen = 0; | |
1375 | { | |
1376 | unsigned char seq[4]; | |
1377 | ssh->scmac->start(ssh->sc_mac_ctx); | |
1378 | PUT_32BIT(seq, st->incoming_sequence); | |
1379 | ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4); | |
1380 | } | |
1381 | ||
1382 | for (;;) { /* Once around this loop per cipher block. */ | |
1383 | /* Read another cipher-block's worth, and tack it onto the end. */ | |
1384 | for (st->i = 0; st->i < st->cipherblk; st->i++) { | |
1385 | while ((*datalen) == 0) | |
1386 | crReturn(NULL); | |
1387 | st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++; | |
1388 | (*datalen)--; | |
1389 | } | |
1390 | /* Decrypt one more block (a little further back in the stream). */ | |
1391 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, | |
1392 | st->pktin->data + st->packetlen, | |
1393 | st->cipherblk); | |
1394 | /* Feed that block to the MAC. */ | |
1395 | ssh->scmac->bytes(ssh->sc_mac_ctx, | |
1396 | st->pktin->data + st->packetlen, st->cipherblk); | |
1397 | st->packetlen += st->cipherblk; | |
1398 | /* See if that gives us a valid packet. */ | |
1399 | if (ssh->scmac->verresult(ssh->sc_mac_ctx, | |
1400 | st->pktin->data + st->packetlen) && | |
1401 | (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen) | |
1402 | break; | |
1403 | if (st->packetlen >= OUR_V2_PACKETLIMIT) { | |
1404 | bombout(("No valid incoming packet found")); | |
1405 | ssh_free_packet(st->pktin); | |
1406 | crStop(NULL); | |
1407 | } | |
1408 | } | |
1409 | st->pktin->maxlen = st->packetlen + st->maclen; | |
1410 | st->pktin->data = sresize(st->pktin->data, | |
1411 | st->pktin->maxlen + APIEXTRA, | |
1412 | unsigned char); | |
1413 | } else { | |
1414 | st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char); | |
1415 | ||
1416 | /* | |
1417 | * Acquire and decrypt the first block of the packet. This will | |
1418 | * contain the length and padding details. | |
1419 | */ | |
1420 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { | |
1421 | while ((*datalen) == 0) | |
1422 | crReturn(NULL); | |
1423 | st->pktin->data[st->i] = *(*data)++; | |
1424 | (*datalen)--; | |
1425 | } | |
1426 | ||
1427 | if (ssh->sccipher) | |
1428 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, | |
1429 | st->pktin->data, st->cipherblk); | |
1430 | ||
1431 | /* | |
1432 | * Now get the length figure. | |
1433 | */ | |
1434 | st->len = GET_32BIT(st->pktin->data); | |
1435 | ||
1436 | /* | |
1437 | * _Completely_ silly lengths should be stomped on before they | |
1438 | * do us any more damage. | |
1439 | */ | |
1440 | if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT || | |
1441 | (st->len + 4) % st->cipherblk != 0) { | |
1442 | bombout(("Incoming packet was garbled on decryption")); | |
1443 | ssh_free_packet(st->pktin); | |
1444 | crStop(NULL); | |
1445 | } | |
1446 | ||
1447 | /* | |
1448 | * So now we can work out the total packet length. | |
1449 | */ | |
1450 | st->packetlen = st->len + 4; | |
1451 | ||
1452 | /* | |
1453 | * Allocate memory for the rest of the packet. | |
1454 | */ | |
1455 | st->pktin->maxlen = st->packetlen + st->maclen; | |
1456 | st->pktin->data = sresize(st->pktin->data, | |
1457 | st->pktin->maxlen + APIEXTRA, | |
1458 | unsigned char); | |
1459 | ||
1460 | /* | |
1461 | * Read and decrypt the remainder of the packet. | |
1462 | */ | |
1463 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; | |
1464 | st->i++) { | |
1465 | while ((*datalen) == 0) | |
1466 | crReturn(NULL); | |
1467 | st->pktin->data[st->i] = *(*data)++; | |
1468 | (*datalen)--; | |
1469 | } | |
1470 | /* Decrypt everything _except_ the MAC. */ | |
1471 | if (ssh->sccipher) | |
1472 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, | |
1473 | st->pktin->data + st->cipherblk, | |
1474 | st->packetlen - st->cipherblk); | |
1475 | ||
1476 | /* | |
1477 | * Check the MAC. | |
1478 | */ | |
1479 | if (ssh->scmac | |
1480 | && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, | |
1481 | st->len + 4, st->incoming_sequence)) { | |
1482 | bombout(("Incorrect MAC received on packet")); | |
1483 | ssh_free_packet(st->pktin); | |
1484 | crStop(NULL); | |
1485 | } | |
1486 | } | |
1487 | /* Get and sanity-check the amount of random padding. */ | |
1488 | st->pad = st->pktin->data[4]; | |
1489 | if (st->pad < 4 || st->len - st->pad < 1) { | |
1490 | bombout(("Invalid padding length on received packet")); | |
1491 | ssh_free_packet(st->pktin); | |
1492 | crStop(NULL); | |
1493 | } | |
1494 | /* | |
1495 | * This enables us to deduce the payload length. | |
1496 | */ | |
1497 | st->payload = st->len - st->pad - 1; | |
1498 | ||
1499 | st->pktin->length = st->payload + 5; | |
1500 | st->pktin->encrypted_len = st->packetlen; | |
1501 | ||
1502 | st->pktin->sequence = st->incoming_sequence++; | |
1503 | ||
1504 | /* | |
1505 | * Decompress packet payload. | |
1506 | */ | |
1507 | { | |
1508 | unsigned char *newpayload; | |
1509 | int newlen; | |
1510 | if (ssh->sccomp && | |
1511 | ssh->sccomp->decompress(ssh->sc_comp_ctx, | |
1512 | st->pktin->data + 5, st->pktin->length - 5, | |
1513 | &newpayload, &newlen)) { | |
1514 | if (st->pktin->maxlen < newlen + 5) { | |
1515 | st->pktin->maxlen = newlen + 5; | |
1516 | st->pktin->data = sresize(st->pktin->data, | |
1517 | st->pktin->maxlen + APIEXTRA, | |
1518 | unsigned char); | |
1519 | } | |
1520 | st->pktin->length = 5 + newlen; | |
1521 | memcpy(st->pktin->data + 5, newpayload, newlen); | |
1522 | sfree(newpayload); | |
1523 | } | |
1524 | } | |
1525 | ||
1526 | st->pktin->savedpos = 6; | |
1527 | st->pktin->body = st->pktin->data; | |
1528 | st->pktin->type = st->pktin->data[5]; | |
1529 | ||
1530 | /* | |
1531 | * Log incoming packet, possibly omitting sensitive fields. | |
1532 | */ | |
1533 | if (ssh->logctx) { | |
1534 | int nblanks = 0; | |
1535 | struct logblank_t blank; | |
1536 | if (ssh->cfg.logomitdata) { | |
1537 | int do_blank = FALSE, blank_prefix = 0; | |
1538 | /* "Session data" packets - omit the data field */ | |
1539 | if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) { | |
1540 | do_blank = TRUE; blank_prefix = 8; | |
1541 | } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { | |
1542 | do_blank = TRUE; blank_prefix = 12; | |
1543 | } | |
1544 | if (do_blank) { | |
1545 | blank.offset = blank_prefix; | |
1546 | blank.len = (st->pktin->length-6) - blank_prefix; | |
1547 | blank.type = PKTLOG_OMIT; | |
1548 | nblanks = 1; | |
1549 | } | |
1550 | } | |
1551 | log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type, | |
1552 | ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, | |
1553 | st->pktin->type), | |
1554 | st->pktin->data+6, st->pktin->length-6, | |
1555 | nblanks, &blank, &st->pktin->sequence); | |
1556 | } | |
1557 | ||
1558 | crFinish(st->pktin); | |
1559 | } | |
1560 | ||
1561 | static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p) | |
1562 | { | |
1563 | int pad, biglen, i, pktoffs; | |
1564 | unsigned long crc; | |
1565 | #ifdef __SC__ | |
1566 | /* | |
1567 | * XXX various versions of SC (including 8.8.4) screw up the | |
1568 | * register allocation in this function and use the same register | |
1569 | * (D6) for len and as a temporary, with predictable results. The | |
1570 | * following sledgehammer prevents this. | |
1571 | */ | |
1572 | volatile | |
1573 | #endif | |
1574 | int len; | |
1575 | ||
1576 | if (ssh->logctx) | |
1577 | log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12], | |
1578 | ssh1_pkt_type(pkt->data[12]), | |
1579 | pkt->body, pkt->length - (pkt->body - pkt->data), | |
1580 | pkt->nblanks, pkt->blanks, NULL); | |
1581 | sfree(pkt->blanks); pkt->blanks = NULL; | |
1582 | pkt->nblanks = 0; | |
1583 | ||
1584 | if (ssh->v1_compressing) { | |
1585 | unsigned char *compblk; | |
1586 | int complen; | |
1587 | zlib_compress_block(ssh->cs_comp_ctx, | |
1588 | pkt->data + 12, pkt->length - 12, | |
1589 | &compblk, &complen); | |
1590 | ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */ | |
1591 | memcpy(pkt->data + 12, compblk, complen); | |
1592 | sfree(compblk); | |
1593 | pkt->length = complen + 12; | |
1594 | } | |
1595 | ||
1596 | ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */ | |
1597 | pkt->length += 4; | |
1598 | len = pkt->length - 4 - 8; /* len(type+data+CRC) */ | |
1599 | pad = 8 - (len % 8); | |
1600 | pktoffs = 8 - pad; | |
1601 | biglen = len + pad; /* len(padding+type+data+CRC) */ | |
1602 | ||
1603 | for (i = pktoffs; i < 4+8; i++) | |
1604 | pkt->data[i] = random_byte(); | |
1605 | crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */ | |
1606 | PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc); | |
1607 | PUT_32BIT(pkt->data + pktoffs, len); | |
1608 | ||
1609 | if (ssh->cipher) | |
1610 | ssh->cipher->encrypt(ssh->v1_cipher_ctx, | |
1611 | pkt->data + pktoffs + 4, biglen); | |
1612 | ||
1613 | if (offset_p) *offset_p = pktoffs; | |
1614 | return biglen + 4; /* len(length+padding+type+data+CRC) */ | |
1615 | } | |
1616 | ||
1617 | static int s_write(Ssh ssh, void *data, int len) | |
1618 | { | |
1619 | if (ssh->logctx) | |
1620 | log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, | |
1621 | 0, NULL, NULL); | |
1622 | return sk_write(ssh->s, (char *)data, len); | |
1623 | } | |
1624 | ||
1625 | static void s_wrpkt(Ssh ssh, struct Packet *pkt) | |
1626 | { | |
1627 | int len, backlog, offset; | |
1628 | len = s_wrpkt_prepare(ssh, pkt, &offset); | |
1629 | backlog = s_write(ssh, pkt->data + offset, len); | |
1630 | if (backlog > SSH_MAX_BACKLOG) | |
1631 | ssh_throttle_all(ssh, 1, backlog); | |
1632 | ssh_free_packet(pkt); | |
1633 | } | |
1634 | ||
1635 | static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt) | |
1636 | { | |
1637 | int len, offset; | |
1638 | len = s_wrpkt_prepare(ssh, pkt, &offset); | |
1639 | if (ssh->deferred_len + len > ssh->deferred_size) { | |
1640 | ssh->deferred_size = ssh->deferred_len + len + 128; | |
1641 | ssh->deferred_send_data = sresize(ssh->deferred_send_data, | |
1642 | ssh->deferred_size, | |
1643 | unsigned char); | |
1644 | } | |
1645 | memcpy(ssh->deferred_send_data + ssh->deferred_len, | |
1646 | pkt->data + offset, len); | |
1647 | ssh->deferred_len += len; | |
1648 | ssh_free_packet(pkt); | |
1649 | } | |
1650 | ||
1651 | /* | |
1652 | * Construct a SSH-1 packet with the specified contents. | |
1653 | * (This all-at-once interface used to be the only one, but now SSH-1 | |
1654 | * packets can also be constructed incrementally.) | |
1655 | */ | |
1656 | static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap) | |
1657 | { | |
1658 | int argtype; | |
1659 | Bignum bn; | |
1660 | struct Packet *pkt; | |
1661 | ||
1662 | pkt = ssh1_pkt_init(pkttype); | |
1663 | ||
1664 | while ((argtype = va_arg(ap, int)) != PKT_END) { | |
1665 | unsigned char *argp, argchar; | |
1666 | char *sargp; | |
1667 | unsigned long argint; | |
1668 | int arglen; | |
1669 | switch (argtype) { | |
1670 | /* Actual fields in the packet */ | |
1671 | case PKT_INT: | |
1672 | argint = va_arg(ap, int); | |
1673 | ssh_pkt_adduint32(pkt, argint); | |
1674 | break; | |
1675 | case PKT_CHAR: | |
1676 | argchar = (unsigned char) va_arg(ap, int); | |
1677 | ssh_pkt_addbyte(pkt, argchar); | |
1678 | break; | |
1679 | case PKT_DATA: | |
1680 | argp = va_arg(ap, unsigned char *); | |
1681 | arglen = va_arg(ap, int); | |
1682 | ssh_pkt_adddata(pkt, argp, arglen); | |
1683 | break; | |
1684 | case PKT_STR: | |
1685 | sargp = va_arg(ap, char *); | |
1686 | ssh_pkt_addstring(pkt, sargp); | |
1687 | break; | |
1688 | case PKT_BIGNUM: | |
1689 | bn = va_arg(ap, Bignum); | |
1690 | ssh1_pkt_addmp(pkt, bn); | |
1691 | break; | |
1692 | /* Tokens for modifications to packet logging */ | |
1693 | case PKTT_PASSWORD: | |
1694 | dont_log_password(ssh, pkt, PKTLOG_BLANK); | |
1695 | break; | |
1696 | case PKTT_DATA: | |
1697 | dont_log_data(ssh, pkt, PKTLOG_OMIT); | |
1698 | break; | |
1699 | case PKTT_OTHER: | |
1700 | end_log_omission(ssh, pkt); | |
1701 | break; | |
1702 | } | |
1703 | } | |
1704 | ||
1705 | return pkt; | |
1706 | } | |
1707 | ||
1708 | static void send_packet(Ssh ssh, int pkttype, ...) | |
1709 | { | |
1710 | struct Packet *pkt; | |
1711 | va_list ap; | |
1712 | va_start(ap, pkttype); | |
1713 | pkt = construct_packet(ssh, pkttype, ap); | |
1714 | va_end(ap); | |
1715 | s_wrpkt(ssh, pkt); | |
1716 | } | |
1717 | ||
1718 | static void defer_packet(Ssh ssh, int pkttype, ...) | |
1719 | { | |
1720 | struct Packet *pkt; | |
1721 | va_list ap; | |
1722 | va_start(ap, pkttype); | |
1723 | pkt = construct_packet(ssh, pkttype, ap); | |
1724 | va_end(ap); | |
1725 | s_wrpkt_defer(ssh, pkt); | |
1726 | } | |
1727 | ||
1728 | static int ssh_versioncmp(char *a, char *b) | |
1729 | { | |
1730 | char *ae, *be; | |
1731 | unsigned long av, bv; | |
1732 | ||
1733 | av = strtoul(a, &ae, 10); | |
1734 | bv = strtoul(b, &be, 10); | |
1735 | if (av != bv) | |
1736 | return (av < bv ? -1 : +1); | |
1737 | if (*ae == '.') | |
1738 | ae++; | |
1739 | if (*be == '.') | |
1740 | be++; | |
1741 | av = strtoul(ae, &ae, 10); | |
1742 | bv = strtoul(be, &be, 10); | |
1743 | if (av != bv) | |
1744 | return (av < bv ? -1 : +1); | |
1745 | return 0; | |
1746 | } | |
1747 | ||
1748 | /* | |
1749 | * Utility routines for putting an SSH-protocol `string' and | |
1750 | * `uint32' into a hash state. | |
1751 | */ | |
1752 | static void hash_string(const struct ssh_hash *h, void *s, void *str, int len) | |
1753 | { | |
1754 | unsigned char lenblk[4]; | |
1755 | PUT_32BIT(lenblk, len); | |
1756 | h->bytes(s, lenblk, 4); | |
1757 | h->bytes(s, str, len); | |
1758 | } | |
1759 | ||
1760 | static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i) | |
1761 | { | |
1762 | unsigned char intblk[4]; | |
1763 | PUT_32BIT(intblk, i); | |
1764 | h->bytes(s, intblk, 4); | |
1765 | } | |
1766 | ||
1767 | /* | |
1768 | * Packet construction functions. Mostly shared between SSH-1 and SSH-2. | |
1769 | */ | |
1770 | static void ssh_pkt_ensure(struct Packet *pkt, int length) | |
1771 | { | |
1772 | if (pkt->maxlen < length) { | |
1773 | unsigned char *body = pkt->body; | |
1774 | int offset = body ? body - pkt->data : 0; | |
1775 | pkt->maxlen = length + 256; | |
1776 | pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char); | |
1777 | if (body) pkt->body = pkt->data + offset; | |
1778 | } | |
1779 | } | |
1780 | static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len) | |
1781 | { | |
1782 | if (pkt->logmode != PKTLOG_EMIT) { | |
1783 | pkt->nblanks++; | |
1784 | pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t); | |
1785 | assert(pkt->body); | |
1786 | pkt->blanks[pkt->nblanks-1].offset = pkt->length - | |
1787 | (pkt->body - pkt->data); | |
1788 | pkt->blanks[pkt->nblanks-1].len = len; | |
1789 | pkt->blanks[pkt->nblanks-1].type = pkt->logmode; | |
1790 | } | |
1791 | pkt->length += len; | |
1792 | ssh_pkt_ensure(pkt, pkt->length); | |
1793 | memcpy(pkt->data + pkt->length - len, data, len); | |
1794 | } | |
1795 | static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte) | |
1796 | { | |
1797 | ssh_pkt_adddata(pkt, &byte, 1); | |
1798 | } | |
1799 | static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value) | |
1800 | { | |
1801 | ssh_pkt_adddata(pkt, &value, 1); | |
1802 | } | |
1803 | static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value) | |
1804 | { | |
1805 | unsigned char x[4]; | |
1806 | PUT_32BIT(x, value); | |
1807 | ssh_pkt_adddata(pkt, x, 4); | |
1808 | } | |
1809 | static void ssh_pkt_addstring_start(struct Packet *pkt) | |
1810 | { | |
1811 | ssh_pkt_adduint32(pkt, 0); | |
1812 | pkt->savedpos = pkt->length; | |
1813 | } | |
1814 | static void ssh_pkt_addstring_str(struct Packet *pkt, char *data) | |
1815 | { | |
1816 | ssh_pkt_adddata(pkt, data, strlen(data)); | |
1817 | PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); | |
1818 | } | |
1819 | static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len) | |
1820 | { | |
1821 | ssh_pkt_adddata(pkt, data, len); | |
1822 | PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); | |
1823 | } | |
1824 | static void ssh_pkt_addstring(struct Packet *pkt, char *data) | |
1825 | { | |
1826 | ssh_pkt_addstring_start(pkt); | |
1827 | ssh_pkt_addstring_str(pkt, data); | |
1828 | } | |
1829 | static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b) | |
1830 | { | |
1831 | int len = ssh1_bignum_length(b); | |
1832 | unsigned char *data = snewn(len, unsigned char); | |
1833 | (void) ssh1_write_bignum(data, b); | |
1834 | ssh_pkt_adddata(pkt, data, len); | |
1835 | sfree(data); | |
1836 | } | |
1837 | static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) | |
1838 | { | |
1839 | unsigned char *p; | |
1840 | int i, n = (bignum_bitcount(b) + 7) / 8; | |
1841 | p = snewn(n + 1, unsigned char); | |
1842 | p[0] = 0; | |
1843 | for (i = 1; i <= n; i++) | |
1844 | p[i] = bignum_byte(b, n - i); | |
1845 | i = 0; | |
1846 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) | |
1847 | i++; | |
1848 | memmove(p, p + i, n + 1 - i); | |
1849 | *len = n + 1 - i; | |
1850 | return p; | |
1851 | } | |
1852 | static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b) | |
1853 | { | |
1854 | unsigned char *p; | |
1855 | int len; | |
1856 | p = ssh2_mpint_fmt(b, &len); | |
1857 | ssh_pkt_addstring_start(pkt); | |
1858 | ssh_pkt_addstring_data(pkt, (char *)p, len); | |
1859 | sfree(p); | |
1860 | } | |
1861 | ||
1862 | static struct Packet *ssh1_pkt_init(int pkt_type) | |
1863 | { | |
1864 | struct Packet *pkt = ssh_new_packet(); | |
1865 | pkt->length = 4 + 8; /* space for length + max padding */ | |
1866 | ssh_pkt_addbyte(pkt, pkt_type); | |
1867 | pkt->body = pkt->data + pkt->length; | |
1868 | return pkt; | |
1869 | } | |
1870 | ||
1871 | /* For legacy code (SSH-1 and -2 packet construction used to be separate) */ | |
1872 | #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length) | |
1873 | #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len) | |
1874 | #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte) | |
1875 | #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value) | |
1876 | #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt) | |
1877 | #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data) | |
1878 | #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len) | |
1879 | #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data) | |
1880 | ||
1881 | static struct Packet *ssh2_pkt_init(int pkt_type) | |
1882 | { | |
1883 | struct Packet *pkt = ssh_new_packet(); | |
1884 | pkt->length = 5; /* space for packet length + padding length */ | |
1885 | pkt->forcepad = 0; | |
1886 | ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); | |
1887 | pkt->body = pkt->data + pkt->length; /* after packet type */ | |
1888 | return pkt; | |
1889 | } | |
1890 | ||
1891 | /* | |
1892 | * Construct an SSH-2 final-form packet: compress it, encrypt it, | |
1893 | * put the MAC on it. Final packet, ready to be sent, is stored in | |
1894 | * pkt->data. Total length is returned. | |
1895 | */ | |
1896 | static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) | |
1897 | { | |
1898 | int cipherblk, maclen, padding, i; | |
1899 | ||
1900 | if (ssh->logctx) | |
1901 | log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], | |
1902 | ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]), | |
1903 | pkt->body, pkt->length - (pkt->body - pkt->data), | |
1904 | pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence); | |
1905 | sfree(pkt->blanks); pkt->blanks = NULL; | |
1906 | pkt->nblanks = 0; | |
1907 | ||
1908 | /* | |
1909 | * Compress packet payload. | |
1910 | */ | |
1911 | { | |
1912 | unsigned char *newpayload; | |
1913 | int newlen; | |
1914 | if (ssh->cscomp && | |
1915 | ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5, | |
1916 | pkt->length - 5, | |
1917 | &newpayload, &newlen)) { | |
1918 | pkt->length = 5; | |
1919 | ssh2_pkt_adddata(pkt, newpayload, newlen); | |
1920 | sfree(newpayload); | |
1921 | } | |
1922 | } | |
1923 | ||
1924 | /* | |
1925 | * Add padding. At least four bytes, and must also bring total | |
1926 | * length (minus MAC) up to a multiple of the block size. | |
1927 | * If pkt->forcepad is set, make sure the packet is at least that size | |
1928 | * after padding. | |
1929 | */ | |
1930 | cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ | |
1931 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ | |
1932 | padding = 4; | |
1933 | if (pkt->length + padding < pkt->forcepad) | |
1934 | padding = pkt->forcepad - pkt->length; | |
1935 | padding += | |
1936 | (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk; | |
1937 | assert(padding <= 255); | |
1938 | maclen = ssh->csmac ? ssh->csmac->len : 0; | |
1939 | ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); | |
1940 | pkt->data[4] = padding; | |
1941 | for (i = 0; i < padding; i++) | |
1942 | pkt->data[pkt->length + i] = random_byte(); | |
1943 | PUT_32BIT(pkt->data, pkt->length + padding - 4); | |
1944 | if (ssh->csmac) | |
1945 | ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, | |
1946 | pkt->length + padding, | |
1947 | ssh->v2_outgoing_sequence); | |
1948 | ssh->v2_outgoing_sequence++; /* whether or not we MACed */ | |
1949 | ||
1950 | if (ssh->cscipher) | |
1951 | ssh->cscipher->encrypt(ssh->cs_cipher_ctx, | |
1952 | pkt->data, pkt->length + padding); | |
1953 | ||
1954 | pkt->encrypted_len = pkt->length + padding; | |
1955 | ||
1956 | /* Ready-to-send packet starts at pkt->data. We return length. */ | |
1957 | return pkt->length + padding + maclen; | |
1958 | } | |
1959 | ||
1960 | /* | |
1961 | * Routines called from the main SSH code to send packets. There | |
1962 | * are quite a few of these, because we have two separate | |
1963 | * mechanisms for delaying the sending of packets: | |
1964 | * | |
1965 | * - In order to send an IGNORE message and a password message in | |
1966 | * a single fixed-length blob, we require the ability to | |
1967 | * concatenate the encrypted forms of those two packets _into_ a | |
1968 | * single blob and then pass it to our <network.h> transport | |
1969 | * layer in one go. Hence, there's a deferment mechanism which | |
1970 | * works after packet encryption. | |
1971 | * | |
1972 | * - In order to avoid sending any connection-layer messages | |
1973 | * during repeat key exchange, we have to queue up any such | |
1974 | * outgoing messages _before_ they are encrypted (and in | |
1975 | * particular before they're allocated sequence numbers), and | |
1976 | * then send them once we've finished. | |
1977 | * | |
1978 | * I call these mechanisms `defer' and `queue' respectively, so as | |
1979 | * to distinguish them reasonably easily. | |
1980 | * | |
1981 | * The functions send_noqueue() and defer_noqueue() free the packet | |
1982 | * structure they are passed. Every outgoing packet goes through | |
1983 | * precisely one of these functions in its life; packets passed to | |
1984 | * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of | |
1985 | * these or get queued, and then when the queue is later emptied | |
1986 | * the packets are all passed to defer_noqueue(). | |
1987 | * | |
1988 | * When using a CBC-mode cipher, it's necessary to ensure that an | |
1989 | * attacker can't provide data to be encrypted using an IV that they | |
1990 | * know. We ensure this by prefixing each packet that might contain | |
1991 | * user data with an SSH_MSG_IGNORE. This is done using the deferral | |
1992 | * mechanism, so in this case send_noqueue() ends up redirecting to | |
1993 | * defer_noqueue(). If you don't like this inefficiency, don't use | |
1994 | * CBC. | |
1995 | */ | |
1996 | ||
1997 | static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int); | |
1998 | static void ssh_pkt_defersend(Ssh); | |
1999 | ||
2000 | /* | |
2001 | * Send an SSH-2 packet immediately, without queuing or deferring. | |
2002 | */ | |
2003 | static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) | |
2004 | { | |
2005 | int len; | |
2006 | int backlog; | |
2007 | if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) { | |
2008 | /* We need to send two packets, so use the deferral mechanism. */ | |
2009 | ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); | |
2010 | ssh_pkt_defersend(ssh); | |
2011 | return; | |
2012 | } | |
2013 | len = ssh2_pkt_construct(ssh, pkt); | |
2014 | backlog = s_write(ssh, pkt->data, len); | |
2015 | if (backlog > SSH_MAX_BACKLOG) | |
2016 | ssh_throttle_all(ssh, 1, backlog); | |
2017 | ||
2018 | ssh->outgoing_data_size += pkt->encrypted_len; | |
2019 | if (!ssh->kex_in_progress && | |
2020 | ssh->max_data_size != 0 && | |
2021 | ssh->outgoing_data_size > ssh->max_data_size) | |
2022 | do_ssh2_transport(ssh, "too much data sent", -1, NULL); | |
2023 | ||
2024 | ssh_free_packet(pkt); | |
2025 | } | |
2026 | ||
2027 | /* | |
2028 | * Defer an SSH-2 packet. | |
2029 | */ | |
2030 | static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) | |
2031 | { | |
2032 | int len; | |
2033 | if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) && | |
2034 | ssh->deferred_len == 0 && !noignore && | |
2035 | !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { | |
2036 | /* | |
2037 | * Interpose an SSH_MSG_IGNORE to ensure that user data don't | |
2038 | * get encrypted with a known IV. | |
2039 | */ | |
2040 | struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE); | |
2041 | ssh2_pkt_addstring_start(ipkt); | |
2042 | ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE); | |
2043 | } | |
2044 | len = ssh2_pkt_construct(ssh, pkt); | |
2045 | if (ssh->deferred_len + len > ssh->deferred_size) { | |
2046 | ssh->deferred_size = ssh->deferred_len + len + 128; | |
2047 | ssh->deferred_send_data = sresize(ssh->deferred_send_data, | |
2048 | ssh->deferred_size, | |
2049 | unsigned char); | |
2050 | } | |
2051 | memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len); | |
2052 | ssh->deferred_len += len; | |
2053 | ssh->deferred_data_size += pkt->encrypted_len; | |
2054 | ssh_free_packet(pkt); | |
2055 | } | |
2056 | ||
2057 | /* | |
2058 | * Queue an SSH-2 packet. | |
2059 | */ | |
2060 | static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) | |
2061 | { | |
2062 | assert(ssh->queueing); | |
2063 | ||
2064 | if (ssh->queuelen >= ssh->queuesize) { | |
2065 | ssh->queuesize = ssh->queuelen + 32; | |
2066 | ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *); | |
2067 | } | |
2068 | ||
2069 | ssh->queue[ssh->queuelen++] = pkt; | |
2070 | } | |
2071 | ||
2072 | /* | |
2073 | * Either queue or send a packet, depending on whether queueing is | |
2074 | * set. | |
2075 | */ | |
2076 | static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt) | |
2077 | { | |
2078 | if (ssh->queueing) | |
2079 | ssh2_pkt_queue(ssh, pkt); | |
2080 | else | |
2081 | ssh2_pkt_send_noqueue(ssh, pkt); | |
2082 | } | |
2083 | ||
2084 | /* | |
2085 | * Either queue or defer a packet, depending on whether queueing is | |
2086 | * set. | |
2087 | */ | |
2088 | static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt) | |
2089 | { | |
2090 | if (ssh->queueing) | |
2091 | ssh2_pkt_queue(ssh, pkt); | |
2092 | else | |
2093 | ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); | |
2094 | } | |
2095 | ||
2096 | /* | |
2097 | * Send the whole deferred data block constructed by | |
2098 | * ssh2_pkt_defer() or SSH-1's defer_packet(). | |
2099 | * | |
2100 | * The expected use of the defer mechanism is that you call | |
2101 | * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If | |
2102 | * not currently queueing, this simply sets up deferred_send_data | |
2103 | * and then sends it. If we _are_ currently queueing, the calls to | |
2104 | * ssh2_pkt_defer() put the deferred packets on to the queue | |
2105 | * instead, and therefore ssh_pkt_defersend() has no deferred data | |
2106 | * to send. Hence, there's no need to make it conditional on | |
2107 | * ssh->queueing. | |
2108 | */ | |
2109 | static void ssh_pkt_defersend(Ssh ssh) | |
2110 | { | |
2111 | int backlog; | |
2112 | backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len); | |
2113 | ssh->deferred_len = ssh->deferred_size = 0; | |
2114 | sfree(ssh->deferred_send_data); | |
2115 | ssh->deferred_send_data = NULL; | |
2116 | if (backlog > SSH_MAX_BACKLOG) | |
2117 | ssh_throttle_all(ssh, 1, backlog); | |
2118 | ||
2119 | ssh->outgoing_data_size += ssh->deferred_data_size; | |
2120 | if (!ssh->kex_in_progress && | |
2121 | ssh->max_data_size != 0 && | |
2122 | ssh->outgoing_data_size > ssh->max_data_size) | |
2123 | do_ssh2_transport(ssh, "too much data sent", -1, NULL); | |
2124 | ssh->deferred_data_size = 0; | |
2125 | } | |
2126 | ||
2127 | /* | |
2128 | * Send a packet whose length needs to be disguised (typically | |
2129 | * passwords or keyboard-interactive responses). | |
2130 | */ | |
2131 | static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt, | |
2132 | int padsize) | |
2133 | { | |
2134 | #if 0 | |
2135 | if (0) { | |
2136 | /* | |
2137 | * The simplest way to do this is to adjust the | |
2138 | * variable-length padding field in the outgoing packet. | |
2139 | * | |
2140 | * Currently compiled out, because some Cisco SSH servers | |
2141 | * don't like excessively padded packets (bah, why's it | |
2142 | * always Cisco?) | |
2143 | */ | |
2144 | pkt->forcepad = padsize; | |
2145 | ssh2_pkt_send(ssh, pkt); | |
2146 | } else | |
2147 | #endif | |
2148 | { | |
2149 | /* | |
2150 | * If we can't do that, however, an alternative approach is | |
2151 | * to use the pkt_defer mechanism to bundle the packet | |
2152 | * tightly together with an SSH_MSG_IGNORE such that their | |
2153 | * combined length is a constant. So first we construct the | |
2154 | * final form of this packet and defer its sending. | |
2155 | */ | |
2156 | ssh2_pkt_defer(ssh, pkt); | |
2157 | ||
2158 | /* | |
2159 | * Now construct an SSH_MSG_IGNORE which includes a string | |
2160 | * that's an exact multiple of the cipher block size. (If | |
2161 | * the cipher is NULL so that the block size is | |
2162 | * unavailable, we don't do this trick at all, because we | |
2163 | * gain nothing by it.) | |
2164 | */ | |
2165 | if (ssh->cscipher && | |
2166 | !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { | |
2167 | int stringlen, i; | |
2168 | ||
2169 | stringlen = (256 - ssh->deferred_len); | |
2170 | stringlen += ssh->cscipher->blksize - 1; | |
2171 | stringlen -= (stringlen % ssh->cscipher->blksize); | |
2172 | if (ssh->cscomp) { | |
2173 | /* | |
2174 | * Temporarily disable actual compression, so we | |
2175 | * can guarantee to get this string exactly the | |
2176 | * length we want it. The compression-disabling | |
2177 | * routine should return an integer indicating how | |
2178 | * many bytes we should adjust our string length | |
2179 | * by. | |
2180 | */ | |
2181 | stringlen -= | |
2182 | ssh->cscomp->disable_compression(ssh->cs_comp_ctx); | |
2183 | } | |
2184 | pkt = ssh2_pkt_init(SSH2_MSG_IGNORE); | |
2185 | ssh2_pkt_addstring_start(pkt); | |
2186 | for (i = 0; i < stringlen; i++) { | |
2187 | char c = (char) random_byte(); | |
2188 | ssh2_pkt_addstring_data(pkt, &c, 1); | |
2189 | } | |
2190 | ssh2_pkt_defer(ssh, pkt); | |
2191 | } | |
2192 | ssh_pkt_defersend(ssh); | |
2193 | } | |
2194 | } | |
2195 | ||
2196 | /* | |
2197 | * Send all queued SSH-2 packets. We send them by means of | |
2198 | * ssh2_pkt_defer_noqueue(), in case they included a pair of | |
2199 | * packets that needed to be lumped together. | |
2200 | */ | |
2201 | static void ssh2_pkt_queuesend(Ssh ssh) | |
2202 | { | |
2203 | int i; | |
2204 | ||
2205 | assert(!ssh->queueing); | |
2206 | ||
2207 | for (i = 0; i < ssh->queuelen; i++) | |
2208 | ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE); | |
2209 | ssh->queuelen = 0; | |
2210 | ||
2211 | ssh_pkt_defersend(ssh); | |
2212 | } | |
2213 | ||
2214 | #if 0 | |
2215 | void bndebug(char *string, Bignum b) | |
2216 | { | |
2217 | unsigned char *p; | |
2218 | int i, len; | |
2219 | p = ssh2_mpint_fmt(b, &len); | |
2220 | debug(("%s", string)); | |
2221 | for (i = 0; i < len; i++) | |
2222 | debug((" %02x", p[i])); | |
2223 | debug(("\n")); | |
2224 | sfree(p); | |
2225 | } | |
2226 | #endif | |
2227 | ||
2228 | static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b) | |
2229 | { | |
2230 | unsigned char *p; | |
2231 | int len; | |
2232 | p = ssh2_mpint_fmt(b, &len); | |
2233 | hash_string(h, s, p, len); | |
2234 | sfree(p); | |
2235 | } | |
2236 | ||
2237 | /* | |
2238 | * Packet decode functions for both SSH-1 and SSH-2. | |
2239 | */ | |
2240 | static unsigned long ssh_pkt_getuint32(struct Packet *pkt) | |
2241 | { | |
2242 | unsigned long value; | |
2243 | if (pkt->length - pkt->savedpos < 4) | |
2244 | return 0; /* arrgh, no way to decline (FIXME?) */ | |
2245 | value = GET_32BIT(pkt->body + pkt->savedpos); | |
2246 | pkt->savedpos += 4; | |
2247 | return value; | |
2248 | } | |
2249 | static int ssh2_pkt_getbool(struct Packet *pkt) | |
2250 | { | |
2251 | unsigned long value; | |
2252 | if (pkt->length - pkt->savedpos < 1) | |
2253 | return 0; /* arrgh, no way to decline (FIXME?) */ | |
2254 | value = pkt->body[pkt->savedpos] != 0; | |
2255 | pkt->savedpos++; | |
2256 | return value; | |
2257 | } | |
2258 | static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length) | |
2259 | { | |
2260 | int len; | |
2261 | *p = NULL; | |
2262 | *length = 0; | |
2263 | if (pkt->length - pkt->savedpos < 4) | |
2264 | return; | |
2265 | len = GET_32BIT(pkt->body + pkt->savedpos); | |
2266 | if (len < 0) | |
2267 | return; | |
2268 | *length = len; | |
2269 | pkt->savedpos += 4; | |
2270 | if (pkt->length - pkt->savedpos < *length) | |
2271 | return; | |
2272 | *p = (char *)(pkt->body + pkt->savedpos); | |
2273 | pkt->savedpos += *length; | |
2274 | } | |
2275 | static void *ssh_pkt_getdata(struct Packet *pkt, int length) | |
2276 | { | |
2277 | if (pkt->length - pkt->savedpos < length) | |
2278 | return NULL; | |
2279 | pkt->savedpos += length; | |
2280 | return pkt->body + (pkt->savedpos - length); | |
2281 | } | |
2282 | static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key, | |
2283 | unsigned char **keystr) | |
2284 | { | |
2285 | int j; | |
2286 | ||
2287 | j = makekey(pkt->body + pkt->savedpos, | |
2288 | pkt->length - pkt->savedpos, | |
2289 | key, keystr, 0); | |
2290 | ||
2291 | if (j < 0) | |
2292 | return FALSE; | |
2293 | ||
2294 | pkt->savedpos += j; | |
2295 | assert(pkt->savedpos < pkt->length); | |
2296 | ||
2297 | return TRUE; | |
2298 | } | |
2299 | static Bignum ssh1_pkt_getmp(struct Packet *pkt) | |
2300 | { | |
2301 | int j; | |
2302 | Bignum b; | |
2303 | ||
2304 | j = ssh1_read_bignum(pkt->body + pkt->savedpos, | |
2305 | pkt->length - pkt->savedpos, &b); | |
2306 | ||
2307 | if (j < 0) | |
2308 | return NULL; | |
2309 | ||
2310 | pkt->savedpos += j; | |
2311 | return b; | |
2312 | } | |
2313 | static Bignum ssh2_pkt_getmp(struct Packet *pkt) | |
2314 | { | |
2315 | char *p; | |
2316 | int length; | |
2317 | Bignum b; | |
2318 | ||
2319 | ssh_pkt_getstring(pkt, &p, &length); | |
2320 | if (!p) | |
2321 | return NULL; | |
2322 | if (p[0] & 0x80) | |
2323 | return NULL; | |
2324 | b = bignum_from_bytes((unsigned char *)p, length); | |
2325 | return b; | |
2326 | } | |
2327 | ||
2328 | /* | |
2329 | * Helper function to add an SSH-2 signature blob to a packet. | |
2330 | * Expects to be shown the public key blob as well as the signature | |
2331 | * blob. Normally works just like ssh2_pkt_addstring, but will | |
2332 | * fiddle with the signature packet if necessary for | |
2333 | * BUG_SSH2_RSA_PADDING. | |
2334 | */ | |
2335 | static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, | |
2336 | void *pkblob_v, int pkblob_len, | |
2337 | void *sigblob_v, int sigblob_len) | |
2338 | { | |
2339 | unsigned char *pkblob = (unsigned char *)pkblob_v; | |
2340 | unsigned char *sigblob = (unsigned char *)sigblob_v; | |
2341 | ||
2342 | /* dmemdump(pkblob, pkblob_len); */ | |
2343 | /* dmemdump(sigblob, sigblob_len); */ | |
2344 | ||
2345 | /* | |
2346 | * See if this is in fact an ssh-rsa signature and a buggy | |
2347 | * server; otherwise we can just do this the easy way. | |
2348 | */ | |
2349 | if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && | |
2350 | (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { | |
2351 | int pos, len, siglen; | |
2352 | ||
2353 | /* | |
2354 | * Find the byte length of the modulus. | |
2355 | */ | |
2356 | ||
2357 | pos = 4+7; /* skip over "ssh-rsa" */ | |
2358 | pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */ | |
2359 | len = GET_32BIT(pkblob+pos); /* find length of modulus */ | |
2360 | pos += 4; /* find modulus itself */ | |
2361 | while (len > 0 && pkblob[pos] == 0) | |
2362 | len--, pos++; | |
2363 | /* debug(("modulus length is %d\n", len)); */ | |
2364 | ||
2365 | /* | |
2366 | * Now find the signature integer. | |
2367 | */ | |
2368 | pos = 4+7; /* skip over "ssh-rsa" */ | |
2369 | siglen = GET_32BIT(sigblob+pos); | |
2370 | /* debug(("signature length is %d\n", siglen)); */ | |
2371 | ||
2372 | if (len != siglen) { | |
2373 | unsigned char newlen[4]; | |
2374 | ssh2_pkt_addstring_start(pkt); | |
2375 | ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos); | |
2376 | /* dmemdump(sigblob, pos); */ | |
2377 | pos += 4; /* point to start of actual sig */ | |
2378 | PUT_32BIT(newlen, len); | |
2379 | ssh2_pkt_addstring_data(pkt, (char *)newlen, 4); | |
2380 | /* dmemdump(newlen, 4); */ | |
2381 | newlen[0] = 0; | |
2382 | while (len-- > siglen) { | |
2383 | ssh2_pkt_addstring_data(pkt, (char *)newlen, 1); | |
2384 | /* dmemdump(newlen, 1); */ | |
2385 | } | |
2386 | ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen); | |
2387 | /* dmemdump(sigblob+pos, siglen); */ | |
2388 | return; | |
2389 | } | |
2390 | ||
2391 | /* Otherwise fall through and do it the easy way. */ | |
2392 | } | |
2393 | ||
2394 | ssh2_pkt_addstring_start(pkt); | |
2395 | ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len); | |
2396 | } | |
2397 | ||
2398 | /* | |
2399 | * Examine the remote side's version string and compare it against | |
2400 | * a list of known buggy implementations. | |
2401 | */ | |
2402 | static void ssh_detect_bugs(Ssh ssh, char *vstring) | |
2403 | { | |
2404 | char *imp; /* pointer to implementation part */ | |
2405 | imp = vstring; | |
2406 | imp += strcspn(imp, "-"); | |
2407 | if (*imp) imp++; | |
2408 | imp += strcspn(imp, "-"); | |
2409 | if (*imp) imp++; | |
2410 | ||
2411 | ssh->remote_bugs = 0; | |
2412 | ||
2413 | /* | |
2414 | * General notes on server version strings: | |
2415 | * - Not all servers reporting "Cisco-1.25" have all the bugs listed | |
2416 | * here -- in particular, we've heard of one that's perfectly happy | |
2417 | * with SSH1_MSG_IGNOREs -- but this string never seems to change, | |
2418 | * so we can't distinguish them. | |
2419 | */ | |
2420 | if (ssh->cfg.sshbug_ignore1 == FORCE_ON || | |
2421 | (ssh->cfg.sshbug_ignore1 == AUTO && | |
2422 | (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || | |
2423 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || | |
2424 | !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") || | |
2425 | !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) { | |
2426 | /* | |
2427 | * These versions don't support SSH1_MSG_IGNORE, so we have | |
2428 | * to use a different defence against password length | |
2429 | * sniffing. | |
2430 | */ | |
2431 | ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; | |
2432 | logevent("We believe remote version has SSH-1 ignore bug"); | |
2433 | } | |
2434 | ||
2435 | if (ssh->cfg.sshbug_plainpw1 == FORCE_ON || | |
2436 | (ssh->cfg.sshbug_plainpw1 == AUTO && | |
2437 | (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) { | |
2438 | /* | |
2439 | * These versions need a plain password sent; they can't | |
2440 | * handle having a null and a random length of data after | |
2441 | * the password. | |
2442 | */ | |
2443 | ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; | |
2444 | logevent("We believe remote version needs a plain SSH-1 password"); | |
2445 | } | |
2446 | ||
2447 | if (ssh->cfg.sshbug_rsa1 == FORCE_ON || | |
2448 | (ssh->cfg.sshbug_rsa1 == AUTO && | |
2449 | (!strcmp(imp, "Cisco-1.25")))) { | |
2450 | /* | |
2451 | * These versions apparently have no clue whatever about | |
2452 | * RSA authentication and will panic and die if they see | |
2453 | * an AUTH_RSA message. | |
2454 | */ | |
2455 | ssh->remote_bugs |= BUG_CHOKES_ON_RSA; | |
2456 | logevent("We believe remote version can't handle SSH-1 RSA authentication"); | |
2457 | } | |
2458 | ||
2459 | if (ssh->cfg.sshbug_hmac2 == FORCE_ON || | |
2460 | (ssh->cfg.sshbug_hmac2 == AUTO && | |
2461 | !wc_match("* VShell", imp) && | |
2462 | (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) || | |
2463 | wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) || | |
2464 | wc_match("2.1 *", imp)))) { | |
2465 | /* | |
2466 | * These versions have the HMAC bug. | |
2467 | */ | |
2468 | ssh->remote_bugs |= BUG_SSH2_HMAC; | |
2469 | logevent("We believe remote version has SSH-2 HMAC bug"); | |
2470 | } | |
2471 | ||
2472 | if (ssh->cfg.sshbug_derivekey2 == FORCE_ON || | |
2473 | (ssh->cfg.sshbug_derivekey2 == AUTO && | |
2474 | !wc_match("* VShell", imp) && | |
2475 | (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) { | |
2476 | /* | |
2477 | * These versions have the key-derivation bug (failing to | |
2478 | * include the literal shared secret in the hashes that | |
2479 | * generate the keys). | |
2480 | */ | |
2481 | ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; | |
2482 | logevent("We believe remote version has SSH-2 key-derivation bug"); | |
2483 | } | |
2484 | ||
2485 | if (ssh->cfg.sshbug_rsapad2 == FORCE_ON || | |
2486 | (ssh->cfg.sshbug_rsapad2 == AUTO && | |
2487 | (wc_match("OpenSSH_2.[5-9]*", imp) || | |
2488 | wc_match("OpenSSH_3.[0-2]*", imp)))) { | |
2489 | /* | |
2490 | * These versions have the SSH-2 RSA padding bug. | |
2491 | */ | |
2492 | ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; | |
2493 | logevent("We believe remote version has SSH-2 RSA padding bug"); | |
2494 | } | |
2495 | ||
2496 | if (ssh->cfg.sshbug_pksessid2 == FORCE_ON || | |
2497 | (ssh->cfg.sshbug_pksessid2 == AUTO && | |
2498 | wc_match("OpenSSH_2.[0-2]*", imp))) { | |
2499 | /* | |
2500 | * These versions have the SSH-2 session-ID bug in | |
2501 | * public-key authentication. | |
2502 | */ | |
2503 | ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; | |
2504 | logevent("We believe remote version has SSH-2 public-key-session-ID bug"); | |
2505 | } | |
2506 | ||
2507 | if (ssh->cfg.sshbug_rekey2 == FORCE_ON || | |
2508 | (ssh->cfg.sshbug_rekey2 == AUTO && | |
2509 | (wc_match("DigiSSH_2.0", imp) || | |
2510 | wc_match("OpenSSH_2.[0-4]*", imp) || | |
2511 | wc_match("OpenSSH_2.5.[0-3]*", imp) || | |
2512 | wc_match("Sun_SSH_1.0", imp) || | |
2513 | wc_match("Sun_SSH_1.0.1", imp) || | |
2514 | /* All versions <= 1.2.6 (they changed their format in 1.2.7) */ | |
2515 | wc_match("WeOnlyDo-*", imp)))) { | |
2516 | /* | |
2517 | * These versions have the SSH-2 rekey bug. | |
2518 | */ | |
2519 | ssh->remote_bugs |= BUG_SSH2_REKEY; | |
2520 | logevent("We believe remote version has SSH-2 rekey bug"); | |
2521 | } | |
2522 | ||
2523 | if (ssh->cfg.sshbug_maxpkt2 == FORCE_ON || | |
2524 | (ssh->cfg.sshbug_maxpkt2 == AUTO && | |
2525 | (wc_match("1.36_sshlib GlobalSCAPE", imp) || | |
2526 | wc_match("1.36 sshlib: GlobalScape", imp)))) { | |
2527 | /* | |
2528 | * This version ignores our makpkt and needs to be throttled. | |
2529 | */ | |
2530 | ssh->remote_bugs |= BUG_SSH2_MAXPKT; | |
2531 | logevent("We believe remote version ignores SSH-2 maximum packet size"); | |
2532 | } | |
2533 | ||
2534 | if (ssh->cfg.sshbug_ignore2 == FORCE_ON) { | |
2535 | /* | |
2536 | * Servers that don't support SSH2_MSG_IGNORE. Currently, | |
2537 | * none detected automatically. | |
2538 | */ | |
2539 | ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE; | |
2540 | logevent("We believe remote version has SSH-2 ignore bug"); | |
2541 | } | |
2542 | } | |
2543 | ||
2544 | /* | |
2545 | * The `software version' part of an SSH version string is required | |
2546 | * to contain no spaces or minus signs. | |
2547 | */ | |
2548 | static void ssh_fix_verstring(char *str) | |
2549 | { | |
2550 | /* Eat "SSH-<protoversion>-". */ | |
2551 | assert(*str == 'S'); str++; | |
2552 | assert(*str == 'S'); str++; | |
2553 | assert(*str == 'H'); str++; | |
2554 | assert(*str == '-'); str++; | |
2555 | while (*str && *str != '-') str++; | |
2556 | assert(*str == '-'); str++; | |
2557 | ||
2558 | /* Convert minus signs and spaces in the remaining string into | |
2559 | * underscores. */ | |
2560 | while (*str) { | |
2561 | if (*str == '-' || *str == ' ') | |
2562 | *str = '_'; | |
2563 | str++; | |
2564 | } | |
2565 | } | |
2566 | ||
2567 | /* | |
2568 | * Send an appropriate SSH version string. | |
2569 | */ | |
2570 | static void ssh_send_verstring(Ssh ssh, char *svers) | |
2571 | { | |
2572 | char *verstring; | |
2573 | ||
2574 | if (ssh->version == 2) { | |
2575 | /* | |
2576 | * Construct a v2 version string. | |
2577 | */ | |
2578 | verstring = dupprintf("SSH-2.0-%s\015\012", sshver); | |
2579 | } else { | |
2580 | /* | |
2581 | * Construct a v1 version string. | |
2582 | */ | |
2583 | verstring = dupprintf("SSH-%s-%s\012", | |
2584 | (ssh_versioncmp(svers, "1.5") <= 0 ? | |
2585 | svers : "1.5"), | |
2586 | sshver); | |
2587 | } | |
2588 | ||
2589 | ssh_fix_verstring(verstring); | |
2590 | ||
2591 | if (ssh->version == 2) { | |
2592 | size_t len; | |
2593 | /* | |
2594 | * Record our version string. | |
2595 | */ | |
2596 | len = strcspn(verstring, "\015\012"); | |
2597 | ssh->v_c = snewn(len + 1, char); | |
2598 | memcpy(ssh->v_c, verstring, len); | |
2599 | ssh->v_c[len] = 0; | |
2600 | } | |
2601 | ||
2602 | logeventf(ssh, "We claim version: %.*s", | |
2603 | strcspn(verstring, "\015\012"), verstring); | |
2604 | s_write(ssh, verstring, strlen(verstring)); | |
2605 | sfree(verstring); | |
2606 | } | |
2607 | ||
2608 | static int do_ssh_init(Ssh ssh, unsigned char c) | |
2609 | { | |
2610 | struct do_ssh_init_state { | |
2611 | int vslen; | |
2612 | char version[10]; | |
2613 | char *vstring; | |
2614 | int vstrsize; | |
2615 | int i; | |
2616 | int proto1, proto2; | |
2617 | }; | |
2618 | crState(do_ssh_init_state); | |
2619 | ||
2620 | crBegin(ssh->do_ssh_init_crstate); | |
2621 | ||
2622 | /* Search for a line beginning with the string "SSH-" in the input. */ | |
2623 | for (;;) { | |
2624 | if (c != 'S') goto no; | |
2625 | crReturn(1); | |
2626 | if (c != 'S') goto no; | |
2627 | crReturn(1); | |
2628 | if (c != 'H') goto no; | |
2629 | crReturn(1); | |
2630 | if (c != '-') goto no; | |
2631 | break; | |
2632 | no: | |
2633 | while (c != '\012') | |
2634 | crReturn(1); | |
2635 | crReturn(1); | |
2636 | } | |
2637 | ||
2638 | s->vstrsize = 16; | |
2639 | s->vstring = snewn(s->vstrsize, char); | |
2640 | strcpy(s->vstring, "SSH-"); | |
2641 | s->vslen = 4; | |
2642 | s->i = 0; | |
2643 | while (1) { | |
2644 | crReturn(1); /* get another char */ | |
2645 | if (s->vslen >= s->vstrsize - 1) { | |
2646 | s->vstrsize += 16; | |
2647 | s->vstring = sresize(s->vstring, s->vstrsize, char); | |
2648 | } | |
2649 | s->vstring[s->vslen++] = c; | |
2650 | if (s->i >= 0) { | |
2651 | if (c == '-') { | |
2652 | s->version[s->i] = '\0'; | |
2653 | s->i = -1; | |
2654 | } else if (s->i < sizeof(s->version) - 1) | |
2655 | s->version[s->i++] = c; | |
2656 | } else if (c == '\012') | |
2657 | break; | |
2658 | } | |
2659 | ||
2660 | ssh->agentfwd_enabled = FALSE; | |
2661 | ssh->rdpkt2_state.incoming_sequence = 0; | |
2662 | ||
2663 | s->vstring[s->vslen] = 0; | |
2664 | s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ | |
2665 | logeventf(ssh, "Server version: %s", s->vstring); | |
2666 | ssh_detect_bugs(ssh, s->vstring); | |
2667 | ||
2668 | /* | |
2669 | * Decide which SSH protocol version to support. | |
2670 | */ | |
2671 | ||
2672 | /* Anything strictly below "2.0" means protocol 1 is supported. */ | |
2673 | s->proto1 = ssh_versioncmp(s->version, "2.0") < 0; | |
2674 | /* Anything greater or equal to "1.99" means protocol 2 is supported. */ | |
2675 | s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0; | |
2676 | ||
2677 | if (ssh->cfg.sshprot == 0 && !s->proto1) { | |
2678 | bombout(("SSH protocol version 1 required by user but not provided by server")); | |
2679 | crStop(0); | |
2680 | } | |
2681 | if (ssh->cfg.sshprot == 3 && !s->proto2) { | |
2682 | bombout(("SSH protocol version 2 required by user but not provided by server")); | |
2683 | crStop(0); | |
2684 | } | |
2685 | ||
2686 | if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) | |
2687 | ssh->version = 2; | |
2688 | else | |
2689 | ssh->version = 1; | |
2690 | ||
2691 | logeventf(ssh, "Using SSH protocol version %d", ssh->version); | |
2692 | ||
2693 | /* Send the version string, if we haven't already */ | |
2694 | if (ssh->cfg.sshprot != 3) | |
2695 | ssh_send_verstring(ssh, s->version); | |
2696 | ||
2697 | if (ssh->version == 2) { | |
2698 | size_t len; | |
2699 | /* | |
2700 | * Record their version string. | |
2701 | */ | |
2702 | len = strcspn(s->vstring, "\015\012"); | |
2703 | ssh->v_s = snewn(len + 1, char); | |
2704 | memcpy(ssh->v_s, s->vstring, len); | |
2705 | ssh->v_s[len] = 0; | |
2706 | ||
2707 | /* | |
2708 | * Initialise SSH-2 protocol. | |
2709 | */ | |
2710 | ssh->protocol = ssh2_protocol; | |
2711 | ssh2_protocol_setup(ssh); | |
2712 | ssh->s_rdpkt = ssh2_rdpkt; | |
2713 | } else { | |
2714 | /* | |
2715 | * Initialise SSH-1 protocol. | |
2716 | */ | |
2717 | ssh->protocol = ssh1_protocol; | |
2718 | ssh1_protocol_setup(ssh); | |
2719 | ssh->s_rdpkt = ssh1_rdpkt; | |
2720 | } | |
2721 | if (ssh->version == 2) | |
2722 | do_ssh2_transport(ssh, NULL, -1, NULL); | |
2723 | ||
2724 | update_specials_menu(ssh->frontend); | |
2725 | ssh->state = SSH_STATE_BEFORE_SIZE; | |
2726 | ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh); | |
2727 | ||
2728 | sfree(s->vstring); | |
2729 | ||
2730 | crFinish(0); | |
2731 | } | |
2732 | ||
2733 | static void ssh_process_incoming_data(Ssh ssh, | |
2734 | unsigned char **data, int *datalen) | |
2735 | { | |
2736 | struct Packet *pktin; | |
2737 | ||
2738 | pktin = ssh->s_rdpkt(ssh, data, datalen); | |
2739 | if (pktin) { | |
2740 | ssh->protocol(ssh, NULL, 0, pktin); | |
2741 | ssh_free_packet(pktin); | |
2742 | } | |
2743 | } | |
2744 | ||
2745 | static void ssh_queue_incoming_data(Ssh ssh, | |
2746 | unsigned char **data, int *datalen) | |
2747 | { | |
2748 | bufchain_add(&ssh->queued_incoming_data, *data, *datalen); | |
2749 | *data += *datalen; | |
2750 | *datalen = 0; | |
2751 | } | |
2752 | ||
2753 | static void ssh_process_queued_incoming_data(Ssh ssh) | |
2754 | { | |
2755 | void *vdata; | |
2756 | unsigned char *data; | |
2757 | int len, origlen; | |
2758 | ||
2759 | while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { | |
2760 | bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len); | |
2761 | data = vdata; | |
2762 | origlen = len; | |
2763 | ||
2764 | while (!ssh->frozen && len > 0) | |
2765 | ssh_process_incoming_data(ssh, &data, &len); | |
2766 | ||
2767 | if (origlen > len) | |
2768 | bufchain_consume(&ssh->queued_incoming_data, origlen - len); | |
2769 | } | |
2770 | } | |
2771 | ||
2772 | static void ssh_set_frozen(Ssh ssh, int frozen) | |
2773 | { | |
2774 | if (ssh->s) | |
2775 | sk_set_frozen(ssh->s, frozen); | |
2776 | ssh->frozen = frozen; | |
2777 | } | |
2778 | ||
2779 | static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) | |
2780 | { | |
2781 | /* Log raw data, if we're in that mode. */ | |
2782 | if (ssh->logctx) | |
2783 | log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen, | |
2784 | 0, NULL, NULL); | |
2785 | ||
2786 | crBegin(ssh->ssh_gotdata_crstate); | |
2787 | ||
2788 | /* | |
2789 | * To begin with, feed the characters one by one to the | |
2790 | * protocol initialisation / selection function do_ssh_init(). | |
2791 | * When that returns 0, we're done with the initial greeting | |
2792 | * exchange and can move on to packet discipline. | |
2793 | */ | |
2794 | while (1) { | |
2795 | int ret; /* need not be kept across crReturn */ | |
2796 | if (datalen == 0) | |
2797 | crReturnV; /* more data please */ | |
2798 | ret = do_ssh_init(ssh, *data); | |
2799 | data++; | |
2800 | datalen--; | |
2801 | if (ret == 0) | |
2802 | break; | |
2803 | } | |
2804 | ||
2805 | /* | |
2806 | * We emerge from that loop when the initial negotiation is | |
2807 | * over and we have selected an s_rdpkt function. Now pass | |
2808 | * everything to s_rdpkt, and then pass the resulting packets | |
2809 | * to the proper protocol handler. | |
2810 | */ | |
2811 | ||
2812 | while (1) { | |
2813 | while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) { | |
2814 | if (ssh->frozen) { | |
2815 | ssh_queue_incoming_data(ssh, &data, &datalen); | |
2816 | /* This uses up all data and cannot cause anything interesting | |
2817 | * to happen; indeed, for anything to happen at all, we must | |
2818 | * return, so break out. */ | |
2819 | break; | |
2820 | } else if (bufchain_size(&ssh->queued_incoming_data) > 0) { | |
2821 | /* This uses up some or all data, and may freeze the | |
2822 | * session. */ | |
2823 | ssh_process_queued_incoming_data(ssh); | |
2824 | } else { | |
2825 | /* This uses up some or all data, and may freeze the | |
2826 | * session. */ | |
2827 | ssh_process_incoming_data(ssh, &data, &datalen); | |
2828 | } | |
2829 | /* FIXME this is probably EBW. */ | |
2830 | if (ssh->state == SSH_STATE_CLOSED) | |
2831 | return; | |
2832 | } | |
2833 | /* We're out of data. Go and get some more. */ | |
2834 | crReturnV; | |
2835 | } | |
2836 | crFinishV; | |
2837 | } | |
2838 | ||
2839 | static int ssh_do_close(Ssh ssh, int notify_exit) | |
2840 | { | |
2841 | int ret = 0; | |
2842 | struct ssh_channel *c; | |
2843 | ||
2844 | ssh->state = SSH_STATE_CLOSED; | |
2845 | expire_timer_context(ssh); | |
2846 | if (ssh->s) { | |
2847 | sk_close(ssh->s); | |
2848 | ssh->s = NULL; | |
2849 | if (notify_exit) | |
2850 | notify_remote_exit(ssh->frontend); | |
2851 | else | |
2852 | ret = 1; | |
2853 | } | |
2854 | /* | |
2855 | * Now we must shut down any port- and X-forwarded channels going | |
2856 | * through this connection. | |
2857 | */ | |
2858 | if (ssh->channels) { | |
2859 | while (NULL != (c = index234(ssh->channels, 0))) { | |
2860 | switch (c->type) { | |
2861 | case CHAN_X11: | |
2862 | x11_close(c->u.x11.s); | |
2863 | break; | |
2864 | case CHAN_SOCKDATA: | |
2865 | case CHAN_SOCKDATA_DORMANT: | |
2866 | pfd_close(c->u.pfd.s); | |
2867 | break; | |
2868 | } | |
2869 | del234(ssh->channels, c); /* moving next one to index 0 */ | |
2870 | if (ssh->version == 2) | |
2871 | bufchain_clear(&c->v.v2.outbuffer); | |
2872 | sfree(c); | |
2873 | } | |
2874 | } | |
2875 | /* | |
2876 | * Go through port-forwardings, and close any associated | |
2877 | * listening sockets. | |
2878 | */ | |
2879 | if (ssh->portfwds) { | |
2880 | struct ssh_portfwd *pf; | |
2881 | while (NULL != (pf = index234(ssh->portfwds, 0))) { | |
2882 | /* Dispose of any listening socket. */ | |
2883 | if (pf->local) | |
2884 | pfd_terminate(pf->local); | |
2885 | del234(ssh->portfwds, pf); /* moving next one to index 0 */ | |
2886 | free_portfwd(pf); | |
2887 | } | |
2888 | freetree234(ssh->portfwds); | |
2889 | ssh->portfwds = NULL; | |
2890 | } | |
2891 | ||
2892 | return ret; | |
2893 | } | |
2894 | ||
2895 | static void ssh_log(Plug plug, int type, SockAddr addr, int port, | |
2896 | const char *error_msg, int error_code) | |
2897 | { | |
2898 | Ssh ssh = (Ssh) plug; | |
2899 | char addrbuf[256], *msg; | |
2900 | ||
2901 | sk_getaddr(addr, addrbuf, lenof(addrbuf)); | |
2902 | ||
2903 | if (type == 0) | |
2904 | msg = dupprintf("Connecting to %s port %d", addrbuf, port); | |
2905 | else | |
2906 | msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); | |
2907 | ||
2908 | logevent(msg); | |
2909 | sfree(msg); | |
2910 | } | |
2911 | ||
2912 | static int ssh_closing(Plug plug, const char *error_msg, int error_code, | |
2913 | int calling_back) | |
2914 | { | |
2915 | Ssh ssh = (Ssh) plug; | |
2916 | int need_notify = ssh_do_close(ssh, FALSE); | |
2917 | ||
2918 | if (!error_msg) { | |
2919 | if (!ssh->close_expected) | |
2920 | error_msg = "Server unexpectedly closed network connection"; | |
2921 | else | |
2922 | error_msg = "Server closed network connection"; | |
2923 | } | |
2924 | ||
2925 | if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0) | |
2926 | ssh->exitcode = 0; | |
2927 | ||
2928 | if (need_notify) | |
2929 | notify_remote_exit(ssh->frontend); | |
2930 | ||
2931 | if (error_msg) | |
2932 | logevent(error_msg); | |
2933 | if (!ssh->close_expected || !ssh->clean_exit) | |
2934 | connection_fatal(ssh->frontend, "%s", error_msg); | |
2935 | return 0; | |
2936 | } | |
2937 | ||
2938 | static int ssh_receive(Plug plug, int urgent, char *data, int len) | |
2939 | { | |
2940 | Ssh ssh = (Ssh) plug; | |
2941 | ssh_gotdata(ssh, (unsigned char *)data, len); | |
2942 | if (ssh->state == SSH_STATE_CLOSED) { | |
2943 | ssh_do_close(ssh, TRUE); | |
2944 | return 0; | |
2945 | } | |
2946 | return 1; | |
2947 | } | |
2948 | ||
2949 | static void ssh_sent(Plug plug, int bufsize) | |
2950 | { | |
2951 | Ssh ssh = (Ssh) plug; | |
2952 | /* | |
2953 | * If the send backlog on the SSH socket itself clears, we | |
2954 | * should unthrottle the whole world if it was throttled. | |
2955 | */ | |
2956 | if (bufsize < SSH_MAX_BACKLOG) | |
2957 | ssh_throttle_all(ssh, 0, bufsize); | |
2958 | } | |
2959 | ||
2960 | /* | |
2961 | * Connect to specified host and port. | |
2962 | * Returns an error message, or NULL on success. | |
2963 | * Also places the canonical host name into `realhost'. It must be | |
2964 | * freed by the caller. | |
2965 | */ | |
2966 | static const char *connect_to_host(Ssh ssh, char *host, int port, | |
2967 | char **realhost, int nodelay, int keepalive) | |
2968 | { | |
2969 | static const struct plug_function_table fn_table = { | |
2970 | ssh_log, | |
2971 | ssh_closing, | |
2972 | ssh_receive, | |
2973 | ssh_sent, | |
2974 | NULL | |
2975 | }; | |
2976 | ||
2977 | SockAddr addr; | |
2978 | const char *err; | |
2979 | ||
2980 | if (*ssh->cfg.loghost) { | |
2981 | char *colon; | |
2982 | ||
2983 | ssh->savedhost = dupstr(ssh->cfg.loghost); | |
2984 | ssh->savedport = 22; /* default ssh port */ | |
2985 | ||
2986 | /* | |
2987 | * A colon suffix on savedhost also lets us affect | |
2988 | * savedport. | |
2989 | * | |
2990 | * (FIXME: do something about IPv6 address literals here.) | |
2991 | */ | |
2992 | colon = strrchr(ssh->savedhost, ':'); | |
2993 | if (colon) { | |
2994 | *colon++ = '\0'; | |
2995 | if (*colon) | |
2996 | ssh->savedport = atoi(colon); | |
2997 | } | |
2998 | } else { | |
2999 | ssh->savedhost = dupstr(host); | |
3000 | if (port < 0) | |
3001 | port = 22; /* default ssh port */ | |
3002 | ssh->savedport = port; | |
3003 | } | |
3004 | ||
3005 | /* | |
3006 | * Try to find host. | |
3007 | */ | |
3008 | logeventf(ssh, "Looking up host \"%s\"%s", host, | |
3009 | (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : | |
3010 | (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); | |
3011 | addr = name_lookup(host, port, realhost, &ssh->cfg, | |
3012 | ssh->cfg.addressfamily); | |
3013 | if ((err = sk_addr_error(addr)) != NULL) { | |
3014 | sk_addr_free(addr); | |
3015 | return err; | |
3016 | } | |
3017 | ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */ | |
3018 | ||
3019 | /* | |
3020 | * Open socket. | |
3021 | */ | |
3022 | ssh->fn = &fn_table; | |
3023 | ssh->s = new_connection(addr, *realhost, port, | |
3024 | 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg); | |
3025 | if ((err = sk_socket_error(ssh->s)) != NULL) { | |
3026 | ssh->s = NULL; | |
3027 | notify_remote_exit(ssh->frontend); | |
3028 | return err; | |
3029 | } | |
3030 | ||
3031 | /* | |
3032 | * If the SSH version number's fixed, set it now, and if it's SSH-2, | |
3033 | * send the version string too. | |
3034 | */ | |
3035 | if (ssh->cfg.sshprot == 0) | |
3036 | ssh->version = 1; | |
3037 | if (ssh->cfg.sshprot == 3) { | |
3038 | ssh->version = 2; | |
3039 | ssh_send_verstring(ssh, NULL); | |
3040 | } | |
3041 | ||
3042 | /* | |
3043 | * loghost, if configured, overrides realhost. | |
3044 | */ | |
3045 | if (*ssh->cfg.loghost) { | |
3046 | sfree(*realhost); | |
3047 | *realhost = dupstr(ssh->cfg.loghost); | |
3048 | } | |
3049 | ||
3050 | return NULL; | |
3051 | } | |
3052 | ||
3053 | /* | |
3054 | * Throttle or unthrottle the SSH connection. | |
3055 | */ | |
3056 | static void ssh_throttle_conn(Ssh ssh, int adjust) | |
3057 | { | |
3058 | int old_count = ssh->conn_throttle_count; | |
3059 | ssh->conn_throttle_count += adjust; | |
3060 | assert(ssh->conn_throttle_count >= 0); | |
3061 | if (ssh->conn_throttle_count && !old_count) { | |
3062 | ssh_set_frozen(ssh, 1); | |
3063 | } else if (!ssh->conn_throttle_count && old_count) { | |
3064 | ssh_set_frozen(ssh, 0); | |
3065 | } | |
3066 | } | |
3067 | ||
3068 | /* | |
3069 | * Throttle or unthrottle _all_ local data streams (for when sends | |
3070 | * on the SSH connection itself back up). | |
3071 | */ | |
3072 | static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) | |
3073 | { | |
3074 | int i; | |
3075 | struct ssh_channel *c; | |
3076 | ||
3077 | if (enable == ssh->throttled_all) | |
3078 | return; | |
3079 | ssh->throttled_all = enable; | |
3080 | ssh->overall_bufsize = bufsize; | |
3081 | if (!ssh->channels) | |
3082 | return; | |
3083 | for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { | |
3084 | switch (c->type) { | |
3085 | case CHAN_MAINSESSION: | |
3086 | /* | |
3087 | * This is treated separately, outside the switch. | |
3088 | */ | |
3089 | break; | |
3090 | case CHAN_X11: | |
3091 | x11_override_throttle(c->u.x11.s, enable); | |
3092 | break; | |
3093 | case CHAN_AGENT: | |
3094 | /* Agent channels require no buffer management. */ | |
3095 | break; | |
3096 | case CHAN_SOCKDATA: | |
3097 | pfd_override_throttle(c->u.pfd.s, enable); | |
3098 | break; | |
3099 | } | |
3100 | } | |
3101 | } | |
3102 | ||
3103 | static void ssh_agent_callback(void *sshv, void *reply, int replylen) | |
3104 | { | |
3105 | Ssh ssh = (Ssh) sshv; | |
3106 | ||
3107 | ssh->agent_response = reply; | |
3108 | ssh->agent_response_len = replylen; | |
3109 | ||
3110 | if (ssh->version == 1) | |
3111 | do_ssh1_login(ssh, NULL, -1, NULL); | |
3112 | else | |
3113 | do_ssh2_authconn(ssh, NULL, -1, NULL); | |
3114 | } | |
3115 | ||
3116 | static void ssh_dialog_callback(void *sshv, int ret) | |
3117 | { | |
3118 | Ssh ssh = (Ssh) sshv; | |
3119 | ||
3120 | ssh->user_response = ret; | |
3121 | ||
3122 | if (ssh->version == 1) | |
3123 | do_ssh1_login(ssh, NULL, -1, NULL); | |
3124 | else | |
3125 | do_ssh2_transport(ssh, NULL, -1, NULL); | |
3126 | ||
3127 | /* | |
3128 | * This may have unfrozen the SSH connection, so do a | |
3129 | * queued-data run. | |
3130 | */ | |
3131 | ssh_process_queued_incoming_data(ssh); | |
3132 | } | |
3133 | ||
3134 | static void ssh_agentf_callback(void *cv, void *reply, int replylen) | |
3135 | { | |
3136 | struct ssh_channel *c = (struct ssh_channel *)cv; | |
3137 | Ssh ssh = c->ssh; | |
3138 | void *sentreply = reply; | |
3139 | ||
3140 | if (!sentreply) { | |
3141 | /* Fake SSH_AGENT_FAILURE. */ | |
3142 | sentreply = "\0\0\0\1\5"; | |
3143 | replylen = 5; | |
3144 | } | |
3145 | if (ssh->version == 2) { | |
3146 | ssh2_add_channel_data(c, sentreply, replylen); | |
3147 | ssh2_try_send(c); | |
3148 | } else { | |
3149 | send_packet(ssh, SSH1_MSG_CHANNEL_DATA, | |
3150 | PKT_INT, c->remoteid, | |
3151 | PKT_INT, replylen, | |
3152 | PKTT_DATA, | |
3153 | PKT_DATA, sentreply, replylen, | |
3154 | PKTT_OTHER, | |
3155 | PKT_END); | |
3156 | } | |
3157 | if (reply) | |
3158 | sfree(reply); | |
3159 | } | |
3160 | ||
3161 | /* | |
3162 | * Client-initiated disconnection. Send a DISCONNECT if `wire_reason' | |
3163 | * non-NULL, otherwise just close the connection. `client_reason' == NULL | |
3164 | * => log `wire_reason'. | |
3165 | */ | |
3166 | static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, | |
3167 | int code, int clean_exit) | |
3168 | { | |
3169 | char *error; | |
3170 | if (!client_reason) | |
3171 | client_reason = wire_reason; | |
3172 | if (client_reason) | |
3173 | error = dupprintf("Disconnected: %s", client_reason); | |
3174 | else | |
3175 | error = dupstr("Disconnected"); | |
3176 | if (wire_reason) { | |
3177 | if (ssh->version == 1) { | |
3178 | send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason, | |
3179 | PKT_END); | |
3180 | } else if (ssh->version == 2) { | |
3181 | struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); | |
3182 | ssh2_pkt_adduint32(pktout, code); | |
3183 | ssh2_pkt_addstring(pktout, wire_reason); | |
3184 | ssh2_pkt_addstring(pktout, "en"); /* language tag */ | |
3185 | ssh2_pkt_send_noqueue(ssh, pktout); | |
3186 | } | |
3187 | } | |
3188 | ssh->close_expected = TRUE; | |
3189 | ssh->clean_exit = clean_exit; | |
3190 | ssh_closing((Plug)ssh, error, 0, 0); | |
3191 | sfree(error); | |
3192 | } | |
3193 | ||
3194 | /* | |
3195 | * Handle the key exchange and user authentication phases. | |
3196 | */ | |
3197 | static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, | |
3198 | struct Packet *pktin) | |
3199 | { | |
3200 | int i, j, ret; | |
3201 | unsigned char cookie[8], *ptr; | |
3202 | struct RSAKey servkey, hostkey; | |
3203 | struct MD5Context md5c; | |
3204 | struct do_ssh1_login_state { | |
3205 | int len; | |
3206 | unsigned char *rsabuf, *keystr1, *keystr2; | |
3207 | unsigned long supported_ciphers_mask, supported_auths_mask; | |
3208 | int tried_publickey, tried_agent; | |
3209 | int tis_auth_refused, ccard_auth_refused; | |
3210 | unsigned char session_id[16]; | |
3211 | int cipher_type; | |
3212 | char username[100]; | |
3213 | void *publickey_blob; | |
3214 | int publickey_bloblen; | |
3215 | char *publickey_comment; | |
3216 | int publickey_encrypted; | |
3217 | prompts_t *cur_prompt; | |
3218 | char c; | |
3219 | int pwpkt_type; | |
3220 | unsigned char request[5], *response, *p; | |
3221 | int responselen; | |
3222 | int keyi, nkeys; | |
3223 | int authed; | |
3224 | struct RSAKey key; | |
3225 | Bignum challenge; | |
3226 | char *commentp; | |
3227 | int commentlen; | |
3228 | int dlgret; | |
3229 | }; | |
3230 | crState(do_ssh1_login_state); | |
3231 | ||
3232 | crBegin(ssh->do_ssh1_login_crstate); | |
3233 | ||
3234 | if (!pktin) | |
3235 | crWaitUntil(pktin); | |
3236 | ||
3237 | if (pktin->type != SSH1_SMSG_PUBLIC_KEY) { | |
3238 | bombout(("Public key packet not received")); | |
3239 | crStop(0); | |
3240 | } | |
3241 | ||
3242 | logevent("Received public keys"); | |
3243 | ||
3244 | ptr = ssh_pkt_getdata(pktin, 8); | |
3245 | if (!ptr) { | |
3246 | bombout(("SSH-1 public key packet stopped before random cookie")); | |
3247 | crStop(0); | |
3248 | } | |
3249 | memcpy(cookie, ptr, 8); | |
3250 | ||
3251 | if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) || | |
3252 | !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) { | |
3253 | bombout(("Failed to read SSH-1 public keys from public key packet")); | |
3254 | crStop(0); | |
3255 | } | |
3256 | ||
3257 | /* | |
3258 | * Log the host key fingerprint. | |
3259 | */ | |
3260 | { | |
3261 | char logmsg[80]; | |
3262 | logevent("Host key fingerprint is:"); | |
3263 | strcpy(logmsg, " "); | |
3264 | hostkey.comment = NULL; | |
3265 | rsa_fingerprint(logmsg + strlen(logmsg), | |
3266 | sizeof(logmsg) - strlen(logmsg), &hostkey); | |
3267 | logevent(logmsg); | |
3268 | } | |
3269 | ||
3270 | ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin); | |
3271 | s->supported_ciphers_mask = ssh_pkt_getuint32(pktin); | |
3272 | s->supported_auths_mask = ssh_pkt_getuint32(pktin); | |
3273 | if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) | |
3274 | s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA); | |
3275 | ||
3276 | ssh->v1_local_protoflags = | |
3277 | ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; | |
3278 | ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; | |
3279 | ||
3280 | MD5Init(&md5c); | |
3281 | MD5Update(&md5c, s->keystr2, hostkey.bytes); | |
3282 | MD5Update(&md5c, s->keystr1, servkey.bytes); | |
3283 | MD5Update(&md5c, cookie, 8); | |
3284 | MD5Final(s->session_id, &md5c); | |
3285 | ||
3286 | for (i = 0; i < 32; i++) | |
3287 | ssh->session_key[i] = random_byte(); | |
3288 | ||
3289 | /* | |
3290 | * Verify that the `bits' and `bytes' parameters match. | |
3291 | */ | |
3292 | if (hostkey.bits > hostkey.bytes * 8 || | |
3293 | servkey.bits > servkey.bytes * 8) { | |
3294 | bombout(("SSH-1 public keys were badly formatted")); | |
3295 | crStop(0); | |
3296 | } | |
3297 | ||
3298 | s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); | |
3299 | ||
3300 | s->rsabuf = snewn(s->len, unsigned char); | |
3301 | ||
3302 | /* | |
3303 | * Verify the host key. | |
3304 | */ | |
3305 | { | |
3306 | /* | |
3307 | * First format the key into a string. | |
3308 | */ | |
3309 | int len = rsastr_len(&hostkey); | |
3310 | char fingerprint[100]; | |
3311 | char *keystr = snewn(len, char); | |
3312 | rsastr_fmt(keystr, &hostkey); | |
3313 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); | |
3314 | ||
3315 | ssh_set_frozen(ssh, 1); | |
3316 | s->dlgret = verify_ssh_host_key(ssh->frontend, | |
3317 | ssh->savedhost, ssh->savedport, | |
3318 | "rsa", keystr, fingerprint, | |
3319 | ssh_dialog_callback, ssh); | |
3320 | sfree(keystr); | |
3321 | if (s->dlgret < 0) { | |
3322 | do { | |
3323 | crReturn(0); | |
3324 | if (pktin) { | |
3325 | bombout(("Unexpected data from server while waiting" | |
3326 | " for user host key response")); | |
3327 | crStop(0); | |
3328 | } | |
3329 | } while (pktin || inlen > 0); | |
3330 | s->dlgret = ssh->user_response; | |
3331 | } | |
3332 | ssh_set_frozen(ssh, 0); | |
3333 | ||
3334 | if (s->dlgret == 0) { | |
3335 | ssh_disconnect(ssh, "User aborted at host key verification", | |
3336 | NULL, 0, TRUE); | |
3337 | crStop(0); | |
3338 | } | |
3339 | } | |
3340 | ||
3341 | for (i = 0; i < 32; i++) { | |
3342 | s->rsabuf[i] = ssh->session_key[i]; | |
3343 | if (i < 16) | |
3344 | s->rsabuf[i] ^= s->session_id[i]; | |
3345 | } | |
3346 | ||
3347 | if (hostkey.bytes > servkey.bytes) { | |
3348 | ret = rsaencrypt(s->rsabuf, 32, &servkey); | |
3349 | if (ret) | |
3350 | ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey); | |
3351 | } else { | |
3352 | ret = rsaencrypt(s->rsabuf, 32, &hostkey); | |
3353 | if (ret) | |
3354 | ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); | |
3355 | } | |
3356 | if (!ret) { | |
3357 | bombout(("SSH-1 public key encryptions failed due to bad formatting")); | |
3358 | crStop(0); | |
3359 | } | |
3360 | ||
3361 | logevent("Encrypted session key"); | |
3362 | ||
3363 | { | |
3364 | int cipher_chosen = 0, warn = 0; | |
3365 | char *cipher_string = NULL; | |
3366 | int i; | |
3367 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { | |
3368 | int next_cipher = ssh->cfg.ssh_cipherlist[i]; | |
3369 | if (next_cipher == CIPHER_WARN) { | |
3370 | /* If/when we choose a cipher, warn about it */ | |
3371 | warn = 1; | |
3372 | } else if (next_cipher == CIPHER_AES) { | |
3373 | /* XXX Probably don't need to mention this. */ | |
3374 | logevent("AES not supported in SSH-1, skipping"); | |
3375 | } else { | |
3376 | switch (next_cipher) { | |
3377 | case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; | |
3378 | cipher_string = "3DES"; break; | |
3379 | case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH; | |
3380 | cipher_string = "Blowfish"; break; | |
3381 | case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES; | |
3382 | cipher_string = "single-DES"; break; | |
3383 | } | |
3384 | if (s->supported_ciphers_mask & (1 << s->cipher_type)) | |
3385 | cipher_chosen = 1; | |
3386 | } | |
3387 | } | |
3388 | if (!cipher_chosen) { | |
3389 | if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) | |
3390 | bombout(("Server violates SSH-1 protocol by not " | |
3391 | "supporting 3DES encryption")); | |
3392 | else | |
3393 | /* shouldn't happen */ | |
3394 | bombout(("No supported ciphers found")); | |
3395 | crStop(0); | |
3396 | } | |
3397 | ||
3398 | /* Warn about chosen cipher if necessary. */ | |
3399 | if (warn) { | |
3400 | ssh_set_frozen(ssh, 1); | |
3401 | s->dlgret = askalg(ssh->frontend, "cipher", cipher_string, | |
3402 | ssh_dialog_callback, ssh); | |
3403 | if (s->dlgret < 0) { | |
3404 | do { | |
3405 | crReturn(0); | |
3406 | if (pktin) { | |
3407 | bombout(("Unexpected data from server while waiting" | |
3408 | " for user response")); | |
3409 | crStop(0); | |
3410 | } | |
3411 | } while (pktin || inlen > 0); | |
3412 | s->dlgret = ssh->user_response; | |
3413 | } | |
3414 | ssh_set_frozen(ssh, 0); | |
3415 | if (s->dlgret == 0) { | |
3416 | ssh_disconnect(ssh, "User aborted at cipher warning", NULL, | |
3417 | 0, TRUE); | |
3418 | crStop(0); | |
3419 | } | |
3420 | } | |
3421 | } | |
3422 | ||
3423 | switch (s->cipher_type) { | |
3424 | case SSH_CIPHER_3DES: | |
3425 | logevent("Using 3DES encryption"); | |
3426 | break; | |
3427 | case SSH_CIPHER_DES: | |
3428 | logevent("Using single-DES encryption"); | |
3429 | break; | |
3430 | case SSH_CIPHER_BLOWFISH: | |
3431 | logevent("Using Blowfish encryption"); | |
3432 | break; | |
3433 | } | |
3434 | ||
3435 | send_packet(ssh, SSH1_CMSG_SESSION_KEY, | |
3436 | PKT_CHAR, s->cipher_type, | |
3437 | PKT_DATA, cookie, 8, | |
3438 | PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF, | |
3439 | PKT_DATA, s->rsabuf, s->len, | |
3440 | PKT_INT, ssh->v1_local_protoflags, PKT_END); | |
3441 | ||
3442 | logevent("Trying to enable encryption..."); | |
3443 | ||
3444 | sfree(s->rsabuf); | |
3445 | ||
3446 | ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : | |
3447 | s->cipher_type == SSH_CIPHER_DES ? &ssh_des : | |
3448 | &ssh_3des); | |
3449 | ssh->v1_cipher_ctx = ssh->cipher->make_context(); | |
3450 | ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key); | |
3451 | logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name); | |
3452 | ||
3453 | ssh->crcda_ctx = crcda_make_context(); | |
3454 | logevent("Installing CRC compensation attack detector"); | |
3455 | ||
3456 | if (servkey.modulus) { | |
3457 | sfree(servkey.modulus); | |
3458 | servkey.modulus = NULL; | |
3459 | } | |
3460 | if (servkey.exponent) { | |
3461 | sfree(servkey.exponent); | |
3462 | servkey.exponent = NULL; | |
3463 | } | |
3464 | if (hostkey.modulus) { | |
3465 | sfree(hostkey.modulus); | |
3466 | hostkey.modulus = NULL; | |
3467 | } | |
3468 | if (hostkey.exponent) { | |
3469 | sfree(hostkey.exponent); | |
3470 | hostkey.exponent = NULL; | |
3471 | } | |
3472 | crWaitUntil(pktin); | |
3473 | ||
3474 | if (pktin->type != SSH1_SMSG_SUCCESS) { | |
3475 | bombout(("Encryption not successfully enabled")); | |
3476 | crStop(0); | |
3477 | } | |
3478 | ||
3479 | logevent("Successfully started encryption"); | |
3480 | ||
3481 | fflush(stdout); /* FIXME eh? */ | |
3482 | { | |
3483 | if (!get_remote_username(&ssh->cfg, s->username, | |
3484 | sizeof(s->username))) { | |
3485 | int ret; /* need not be kept over crReturn */ | |
3486 | s->cur_prompt = new_prompts(ssh->frontend); | |
3487 | s->cur_prompt->to_server = TRUE; | |
3488 | s->cur_prompt->name = dupstr("SSH login name"); | |
3489 | add_prompt(s->cur_prompt, dupstr("login as: "), TRUE, | |
3490 | lenof(s->username)); | |
3491 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
3492 | while (ret < 0) { | |
3493 | ssh->send_ok = 1; | |
3494 | crWaitUntil(!pktin); | |
3495 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
3496 | ssh->send_ok = 0; | |
3497 | } | |
3498 | if (!ret) { | |
3499 | /* | |
3500 | * Failed to get a username. Terminate. | |
3501 | */ | |
3502 | free_prompts(s->cur_prompt); | |
3503 | ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); | |
3504 | crStop(0); | |
3505 | } | |
3506 | memcpy(s->username, s->cur_prompt->prompts[0]->result, | |
3507 | lenof(s->username)); | |
3508 | free_prompts(s->cur_prompt); | |
3509 | } | |
3510 | ||
3511 | send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END); | |
3512 | { | |
3513 | char *userlog = dupprintf("Sent username \"%s\"", s->username); | |
3514 | logevent(userlog); | |
3515 | if (flags & FLAG_INTERACTIVE && | |
3516 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { | |
3517 | c_write_str(ssh, userlog); | |
3518 | c_write_str(ssh, "\r\n"); | |
3519 | } | |
3520 | sfree(userlog); | |
3521 | } | |
3522 | } | |
3523 | ||
3524 | crWaitUntil(pktin); | |
3525 | ||
3526 | if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) { | |
3527 | /* We must not attempt PK auth. Pretend we've already tried it. */ | |
3528 | s->tried_publickey = s->tried_agent = 1; | |
3529 | } else { | |
3530 | s->tried_publickey = s->tried_agent = 0; | |
3531 | } | |
3532 | s->tis_auth_refused = s->ccard_auth_refused = 0; | |
3533 | /* | |
3534 | * Load the public half of any configured keyfile for later use. | |
3535 | */ | |
3536 | if (!filename_is_null(ssh->cfg.keyfile)) { | |
3537 | int keytype; | |
3538 | logeventf(ssh, "Reading private key file \"%.150s\"", | |
3539 | filename_to_str(&ssh->cfg.keyfile)); | |
3540 | keytype = key_type(&ssh->cfg.keyfile); | |
3541 | if (keytype == SSH_KEYTYPE_SSH1) { | |
3542 | const char *error; | |
3543 | if (rsakey_pubblob(&ssh->cfg.keyfile, | |
3544 | &s->publickey_blob, &s->publickey_bloblen, | |
3545 | &s->publickey_comment, &error)) { | |
3546 | s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile, | |
3547 | NULL); | |
3548 | } else { | |
3549 | char *msgbuf; | |
3550 | logeventf(ssh, "Unable to load private key (%s)", error); | |
3551 | msgbuf = dupprintf("Unable to load private key file " | |
3552 | "\"%.150s\" (%s)\r\n", | |
3553 | filename_to_str(&ssh->cfg.keyfile), | |
3554 | error); | |
3555 | c_write_str(ssh, msgbuf); | |
3556 | sfree(msgbuf); | |
3557 | s->publickey_blob = NULL; | |
3558 | } | |
3559 | } else { | |
3560 | char *msgbuf; | |
3561 | logeventf(ssh, "Unable to use this key file (%s)", | |
3562 | key_type_to_str(keytype)); | |
3563 | msgbuf = dupprintf("Unable to use key file \"%.150s\"" | |
3564 | " (%s)\r\n", | |
3565 | filename_to_str(&ssh->cfg.keyfile), | |
3566 | key_type_to_str(keytype)); | |
3567 | c_write_str(ssh, msgbuf); | |
3568 | sfree(msgbuf); | |
3569 | s->publickey_blob = NULL; | |
3570 | } | |
3571 | } else | |
3572 | s->publickey_blob = NULL; | |
3573 | ||
3574 | while (pktin->type == SSH1_SMSG_FAILURE) { | |
3575 | s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; | |
3576 | ||
3577 | if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) { | |
3578 | /* | |
3579 | * Attempt RSA authentication using Pageant. | |
3580 | */ | |
3581 | void *r; | |
3582 | ||
3583 | s->authed = FALSE; | |
3584 | s->tried_agent = 1; | |
3585 | logevent("Pageant is running. Requesting keys."); | |
3586 | ||
3587 | /* Request the keys held by the agent. */ | |
3588 | PUT_32BIT(s->request, 1); | |
3589 | s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; | |
3590 | if (!agent_query(s->request, 5, &r, &s->responselen, | |
3591 | ssh_agent_callback, ssh)) { | |
3592 | do { | |
3593 | crReturn(0); | |
3594 | if (pktin) { | |
3595 | bombout(("Unexpected data from server while waiting" | |
3596 | " for agent response")); | |
3597 | crStop(0); | |
3598 | } | |
3599 | } while (pktin || inlen > 0); | |
3600 | r = ssh->agent_response; | |
3601 | s->responselen = ssh->agent_response_len; | |
3602 | } | |
3603 | s->response = (unsigned char *) r; | |
3604 | if (s->response && s->responselen >= 5 && | |
3605 | s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { | |
3606 | s->p = s->response + 5; | |
3607 | s->nkeys = GET_32BIT(s->p); | |
3608 | s->p += 4; | |
3609 | logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); | |
3610 | for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { | |
3611 | unsigned char *pkblob = s->p; | |
3612 | s->p += 4; | |
3613 | { | |
3614 | int n, ok = FALSE; | |
3615 | do { /* do while (0) to make breaking easy */ | |
3616 | n = ssh1_read_bignum | |
3617 | (s->p, s->responselen-(s->p-s->response), | |
3618 | &s->key.exponent); | |
3619 | if (n < 0) | |
3620 | break; | |
3621 | s->p += n; | |
3622 | n = ssh1_read_bignum | |
3623 | (s->p, s->responselen-(s->p-s->response), | |
3624 | &s->key.modulus); | |
3625 | if (n < 0) | |
3626 | break; | |
3627 | s->p += n; | |
3628 | if (s->responselen - (s->p-s->response) < 4) | |
3629 | break; | |
3630 | s->commentlen = GET_32BIT(s->p); | |
3631 | s->p += 4; | |
3632 | if (s->responselen - (s->p-s->response) < | |
3633 | s->commentlen) | |
3634 | break; | |
3635 | s->commentp = (char *)s->p; | |
3636 | s->p += s->commentlen; | |
3637 | ok = TRUE; | |
3638 | } while (0); | |
3639 | if (!ok) { | |
3640 | logevent("Pageant key list packet was truncated"); | |
3641 | break; | |
3642 | } | |
3643 | } | |
3644 | if (s->publickey_blob) { | |
3645 | if (!memcmp(pkblob, s->publickey_blob, | |
3646 | s->publickey_bloblen)) { | |
3647 | logeventf(ssh, "Pageant key #%d matches " | |
3648 | "configured key file", s->keyi); | |
3649 | s->tried_publickey = 1; | |
3650 | } else | |
3651 | /* Skip non-configured key */ | |
3652 | continue; | |
3653 | } | |
3654 | logeventf(ssh, "Trying Pageant key #%d", s->keyi); | |
3655 | send_packet(ssh, SSH1_CMSG_AUTH_RSA, | |
3656 | PKT_BIGNUM, s->key.modulus, PKT_END); | |
3657 | crWaitUntil(pktin); | |
3658 | if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { | |
3659 | logevent("Key refused"); | |
3660 | continue; | |
3661 | } | |
3662 | logevent("Received RSA challenge"); | |
3663 | if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) { | |
3664 | bombout(("Server's RSA challenge was badly formatted")); | |
3665 | crStop(0); | |
3666 | } | |
3667 | ||
3668 | { | |
3669 | char *agentreq, *q, *ret; | |
3670 | void *vret; | |
3671 | int len, retlen; | |
3672 | len = 1 + 4; /* message type, bit count */ | |
3673 | len += ssh1_bignum_length(s->key.exponent); | |
3674 | len += ssh1_bignum_length(s->key.modulus); | |
3675 | len += ssh1_bignum_length(s->challenge); | |
3676 | len += 16; /* session id */ | |
3677 | len += 4; /* response format */ | |
3678 | agentreq = snewn(4 + len, char); | |
3679 | PUT_32BIT(agentreq, len); | |
3680 | q = agentreq + 4; | |
3681 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; | |
3682 | PUT_32BIT(q, bignum_bitcount(s->key.modulus)); | |
3683 | q += 4; | |
3684 | q += ssh1_write_bignum(q, s->key.exponent); | |
3685 | q += ssh1_write_bignum(q, s->key.modulus); | |
3686 | q += ssh1_write_bignum(q, s->challenge); | |
3687 | memcpy(q, s->session_id, 16); | |
3688 | q += 16; | |
3689 | PUT_32BIT(q, 1); /* response format */ | |
3690 | if (!agent_query(agentreq, len + 4, &vret, &retlen, | |
3691 | ssh_agent_callback, ssh)) { | |
3692 | sfree(agentreq); | |
3693 | do { | |
3694 | crReturn(0); | |
3695 | if (pktin) { | |
3696 | bombout(("Unexpected data from server" | |
3697 | " while waiting for agent" | |
3698 | " response")); | |
3699 | crStop(0); | |
3700 | } | |
3701 | } while (pktin || inlen > 0); | |
3702 | vret = ssh->agent_response; | |
3703 | retlen = ssh->agent_response_len; | |
3704 | } else | |
3705 | sfree(agentreq); | |
3706 | ret = vret; | |
3707 | if (ret) { | |
3708 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { | |
3709 | logevent("Sending Pageant's response"); | |
3710 | send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, | |
3711 | PKT_DATA, ret + 5, 16, | |
3712 | PKT_END); | |
3713 | sfree(ret); | |
3714 | crWaitUntil(pktin); | |
3715 | if (pktin->type == SSH1_SMSG_SUCCESS) { | |
3716 | logevent | |
3717 | ("Pageant's response accepted"); | |
3718 | if (flags & FLAG_VERBOSE) { | |
3719 | c_write_str(ssh, "Authenticated using" | |
3720 | " RSA key \""); | |
3721 | c_write(ssh, s->commentp, | |
3722 | s->commentlen); | |
3723 | c_write_str(ssh, "\" from agent\r\n"); | |
3724 | } | |
3725 | s->authed = TRUE; | |
3726 | } else | |
3727 | logevent | |
3728 | ("Pageant's response not accepted"); | |
3729 | } else { | |
3730 | logevent | |
3731 | ("Pageant failed to answer challenge"); | |
3732 | sfree(ret); | |
3733 | } | |
3734 | } else { | |
3735 | logevent("No reply received from Pageant"); | |
3736 | } | |
3737 | } | |
3738 | freebn(s->key.exponent); | |
3739 | freebn(s->key.modulus); | |
3740 | freebn(s->challenge); | |
3741 | if (s->authed) | |
3742 | break; | |
3743 | } | |
3744 | sfree(s->response); | |
3745 | if (s->publickey_blob && !s->tried_publickey) | |
3746 | logevent("Configured key file not in Pageant"); | |
3747 | } else { | |
3748 | logevent("Failed to get reply from Pageant"); | |
3749 | } | |
3750 | if (s->authed) | |
3751 | break; | |
3752 | } | |
3753 | if (s->publickey_blob && !s->tried_publickey) { | |
3754 | /* | |
3755 | * Try public key authentication with the specified | |
3756 | * key file. | |
3757 | */ | |
3758 | int got_passphrase; /* need not be kept over crReturn */ | |
3759 | if (flags & FLAG_VERBOSE) | |
3760 | c_write_str(ssh, "Trying public key authentication.\r\n"); | |
3761 | logeventf(ssh, "Trying public key \"%s\"", | |
3762 | filename_to_str(&ssh->cfg.keyfile)); | |
3763 | s->tried_publickey = 1; | |
3764 | got_passphrase = FALSE; | |
3765 | while (!got_passphrase) { | |
3766 | /* | |
3767 | * Get a passphrase, if necessary. | |
3768 | */ | |
3769 | char *passphrase = NULL; /* only written after crReturn */ | |
3770 | const char *error; | |
3771 | if (!s->publickey_encrypted) { | |
3772 | if (flags & FLAG_VERBOSE) | |
3773 | c_write_str(ssh, "No passphrase required.\r\n"); | |
3774 | passphrase = NULL; | |
3775 | } else { | |
3776 | int ret; /* need not be kept over crReturn */ | |
3777 | s->cur_prompt = new_prompts(ssh->frontend); | |
3778 | s->cur_prompt->to_server = FALSE; | |
3779 | s->cur_prompt->name = dupstr("SSH key passphrase"); | |
3780 | add_prompt(s->cur_prompt, | |
3781 | dupprintf("Passphrase for key \"%.100s\": ", | |
3782 | s->publickey_comment), | |
3783 | FALSE, SSH_MAX_PASSWORD_LEN); | |
3784 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
3785 | while (ret < 0) { | |
3786 | ssh->send_ok = 1; | |
3787 | crWaitUntil(!pktin); | |
3788 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
3789 | ssh->send_ok = 0; | |
3790 | } | |
3791 | if (!ret) { | |
3792 | /* Failed to get a passphrase. Terminate. */ | |
3793 | free_prompts(s->cur_prompt); | |
3794 | ssh_disconnect(ssh, NULL, "Unable to authenticate", | |
3795 | 0, TRUE); | |
3796 | crStop(0); | |
3797 | } | |
3798 | passphrase = dupstr(s->cur_prompt->prompts[0]->result); | |
3799 | free_prompts(s->cur_prompt); | |
3800 | } | |
3801 | /* | |
3802 | * Try decrypting key with passphrase. | |
3803 | */ | |
3804 | ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase, | |
3805 | &error); | |
3806 | if (passphrase) { | |
3807 | memset(passphrase, 0, strlen(passphrase)); | |
3808 | sfree(passphrase); | |
3809 | } | |
3810 | if (ret == 1) { | |
3811 | /* Correct passphrase. */ | |
3812 | got_passphrase = TRUE; | |
3813 | } else if (ret == 0) { | |
3814 | c_write_str(ssh, "Couldn't load private key from "); | |
3815 | c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile)); | |
3816 | c_write_str(ssh, " ("); | |
3817 | c_write_str(ssh, error); | |
3818 | c_write_str(ssh, ").\r\n"); | |
3819 | got_passphrase = FALSE; | |
3820 | break; /* go and try something else */ | |
3821 | } else if (ret == -1) { | |
3822 | c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */ | |
3823 | got_passphrase = FALSE; | |
3824 | /* and try again */ | |
3825 | } else { | |
3826 | assert(0 && "unexpected return from loadrsakey()"); | |
3827 | got_passphrase = FALSE; /* placate optimisers */ | |
3828 | } | |
3829 | } | |
3830 | ||
3831 | if (got_passphrase) { | |
3832 | ||
3833 | /* | |
3834 | * Send a public key attempt. | |
3835 | */ | |
3836 | send_packet(ssh, SSH1_CMSG_AUTH_RSA, | |
3837 | PKT_BIGNUM, s->key.modulus, PKT_END); | |
3838 | ||
3839 | crWaitUntil(pktin); | |
3840 | if (pktin->type == SSH1_SMSG_FAILURE) { | |
3841 | c_write_str(ssh, "Server refused our public key.\r\n"); | |
3842 | continue; /* go and try something else */ | |
3843 | } | |
3844 | if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { | |
3845 | bombout(("Bizarre response to offer of public key")); | |
3846 | crStop(0); | |
3847 | } | |
3848 | ||
3849 | { | |
3850 | int i; | |
3851 | unsigned char buffer[32]; | |
3852 | Bignum challenge, response; | |
3853 | ||
3854 | if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) { | |
3855 | bombout(("Server's RSA challenge was badly formatted")); | |
3856 | crStop(0); | |
3857 | } | |
3858 | response = rsadecrypt(challenge, &s->key); | |
3859 | freebn(s->key.private_exponent);/* burn the evidence */ | |
3860 | ||
3861 | for (i = 0; i < 32; i++) { | |
3862 | buffer[i] = bignum_byte(response, 31 - i); | |
3863 | } | |
3864 | ||
3865 | MD5Init(&md5c); | |
3866 | MD5Update(&md5c, buffer, 32); | |
3867 | MD5Update(&md5c, s->session_id, 16); | |
3868 | MD5Final(buffer, &md5c); | |
3869 | ||
3870 | send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, | |
3871 | PKT_DATA, buffer, 16, PKT_END); | |
3872 | ||
3873 | freebn(challenge); | |
3874 | freebn(response); | |
3875 | } | |
3876 | ||
3877 | crWaitUntil(pktin); | |
3878 | if (pktin->type == SSH1_SMSG_FAILURE) { | |
3879 | if (flags & FLAG_VERBOSE) | |
3880 | c_write_str(ssh, "Failed to authenticate with" | |
3881 | " our public key.\r\n"); | |
3882 | continue; /* go and try something else */ | |
3883 | } else if (pktin->type != SSH1_SMSG_SUCCESS) { | |
3884 | bombout(("Bizarre response to RSA authentication response")); | |
3885 | crStop(0); | |
3886 | } | |
3887 | ||
3888 | break; /* we're through! */ | |
3889 | } | |
3890 | ||
3891 | } | |
3892 | ||
3893 | /* | |
3894 | * Otherwise, try various forms of password-like authentication. | |
3895 | */ | |
3896 | s->cur_prompt = new_prompts(ssh->frontend); | |
3897 | ||
3898 | if (ssh->cfg.try_tis_auth && | |
3899 | (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) && | |
3900 | !s->tis_auth_refused) { | |
3901 | s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; | |
3902 | logevent("Requested TIS authentication"); | |
3903 | send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END); | |
3904 | crWaitUntil(pktin); | |
3905 | if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { | |
3906 | logevent("TIS authentication declined"); | |
3907 | if (flags & FLAG_INTERACTIVE) | |
3908 | c_write_str(ssh, "TIS authentication refused.\r\n"); | |
3909 | s->tis_auth_refused = 1; | |
3910 | continue; | |
3911 | } else { | |
3912 | char *challenge; | |
3913 | int challengelen; | |
3914 | char *instr_suf, *prompt; | |
3915 | ||
3916 | ssh_pkt_getstring(pktin, &challenge, &challengelen); | |
3917 | if (!challenge) { | |
3918 | bombout(("TIS challenge packet was badly formed")); | |
3919 | crStop(0); | |
3920 | } | |
3921 | logevent("Received TIS challenge"); | |
3922 | s->cur_prompt->to_server = TRUE; | |
3923 | s->cur_prompt->name = dupstr("SSH TIS authentication"); | |
3924 | /* Prompt heuristic comes from OpenSSH */ | |
3925 | if (memchr(challenge, '\n', challengelen)) { | |
3926 | instr_suf = dupstr(""); | |
3927 | prompt = dupprintf("%.*s", challengelen, challenge); | |
3928 | } else { | |
3929 | instr_suf = dupprintf("%.*s", challengelen, challenge); | |
3930 | prompt = dupstr("Response: "); | |
3931 | } | |
3932 | s->cur_prompt->instruction = | |
3933 | dupprintf("Using TIS authentication.%s%s", | |
3934 | (*instr_suf) ? "\n" : "", | |
3935 | instr_suf); | |
3936 | s->cur_prompt->instr_reqd = TRUE; | |
3937 | add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN); | |
3938 | sfree(instr_suf); | |
3939 | } | |
3940 | } | |
3941 | if (ssh->cfg.try_tis_auth && | |
3942 | (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && | |
3943 | !s->ccard_auth_refused) { | |
3944 | s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; | |
3945 | logevent("Requested CryptoCard authentication"); | |
3946 | send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END); | |
3947 | crWaitUntil(pktin); | |
3948 | if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { | |
3949 | logevent("CryptoCard authentication declined"); | |
3950 | c_write_str(ssh, "CryptoCard authentication refused.\r\n"); | |
3951 | s->ccard_auth_refused = 1; | |
3952 | continue; | |
3953 | } else { | |
3954 | char *challenge; | |
3955 | int challengelen; | |
3956 | char *instr_suf, *prompt; | |
3957 | ||
3958 | ssh_pkt_getstring(pktin, &challenge, &challengelen); | |
3959 | if (!challenge) { | |
3960 | bombout(("CryptoCard challenge packet was badly formed")); | |
3961 | crStop(0); | |
3962 | } | |
3963 | logevent("Received CryptoCard challenge"); | |
3964 | s->cur_prompt->to_server = TRUE; | |
3965 | s->cur_prompt->name = dupstr("SSH CryptoCard authentication"); | |
3966 | s->cur_prompt->name_reqd = FALSE; | |
3967 | /* Prompt heuristic comes from OpenSSH */ | |
3968 | if (memchr(challenge, '\n', challengelen)) { | |
3969 | instr_suf = dupstr(""); | |
3970 | prompt = dupprintf("%.*s", challengelen, challenge); | |
3971 | } else { | |
3972 | instr_suf = dupprintf("%.*s", challengelen, challenge); | |
3973 | prompt = dupstr("Response: "); | |
3974 | } | |
3975 | s->cur_prompt->instruction = | |
3976 | dupprintf("Using CryptoCard authentication.%s%s", | |
3977 | (*instr_suf) ? "\n" : "", | |
3978 | instr_suf); | |
3979 | s->cur_prompt->instr_reqd = TRUE; | |
3980 | add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN); | |
3981 | sfree(instr_suf); | |
3982 | } | |
3983 | } | |
3984 | if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { | |
3985 | if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) { | |
3986 | bombout(("No supported authentication methods available")); | |
3987 | crStop(0); | |
3988 | } | |
3989 | s->cur_prompt->to_server = TRUE; | |
3990 | s->cur_prompt->name = dupstr("SSH password"); | |
3991 | add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ", | |
3992 | s->username, ssh->savedhost), | |
3993 | FALSE, SSH_MAX_PASSWORD_LEN); | |
3994 | } | |
3995 | ||
3996 | /* | |
3997 | * Show password prompt, having first obtained it via a TIS | |
3998 | * or CryptoCard exchange if we're doing TIS or CryptoCard | |
3999 | * authentication. | |
4000 | */ | |
4001 | { | |
4002 | int ret; /* need not be kept over crReturn */ | |
4003 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
4004 | while (ret < 0) { | |
4005 | ssh->send_ok = 1; | |
4006 | crWaitUntil(!pktin); | |
4007 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
4008 | ssh->send_ok = 0; | |
4009 | } | |
4010 | if (!ret) { | |
4011 | /* | |
4012 | * Failed to get a password (for example | |
4013 | * because one was supplied on the command line | |
4014 | * which has already failed to work). Terminate. | |
4015 | */ | |
4016 | free_prompts(s->cur_prompt); | |
4017 | ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE); | |
4018 | crStop(0); | |
4019 | } | |
4020 | } | |
4021 | ||
4022 | if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { | |
4023 | /* | |
4024 | * Defence against traffic analysis: we send a | |
4025 | * whole bunch of packets containing strings of | |
4026 | * different lengths. One of these strings is the | |
4027 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. | |
4028 | * The others are all random data in | |
4029 | * SSH1_MSG_IGNORE packets. This way a passive | |
4030 | * listener can't tell which is the password, and | |
4031 | * hence can't deduce the password length. | |
4032 | * | |
4033 | * Anybody with a password length greater than 16 | |
4034 | * bytes is going to have enough entropy in their | |
4035 | * password that a listener won't find it _that_ | |
4036 | * much help to know how long it is. So what we'll | |
4037 | * do is: | |
4038 | * | |
4039 | * - if password length < 16, we send 15 packets | |
4040 | * containing string lengths 1 through 15 | |
4041 | * | |
4042 | * - otherwise, we let N be the nearest multiple | |
4043 | * of 8 below the password length, and send 8 | |
4044 | * packets containing string lengths N through | |
4045 | * N+7. This won't obscure the order of | |
4046 | * magnitude of the password length, but it will | |
4047 | * introduce a bit of extra uncertainty. | |
4048 | * | |
4049 | * A few servers can't deal with SSH1_MSG_IGNORE, at | |
4050 | * least in this context. For these servers, we need | |
4051 | * an alternative defence. We make use of the fact | |
4052 | * that the password is interpreted as a C string: | |
4053 | * so we can append a NUL, then some random data. | |
4054 | * | |
4055 | * A few servers can deal with neither SSH1_MSG_IGNORE | |
4056 | * here _nor_ a padded password string. | |
4057 | * For these servers we are left with no defences | |
4058 | * against password length sniffing. | |
4059 | */ | |
4060 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) && | |
4061 | !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { | |
4062 | /* | |
4063 | * The server can deal with SSH1_MSG_IGNORE, so | |
4064 | * we can use the primary defence. | |
4065 | */ | |
4066 | int bottom, top, pwlen, i; | |
4067 | char *randomstr; | |
4068 | ||
4069 | pwlen = strlen(s->cur_prompt->prompts[0]->result); | |
4070 | if (pwlen < 16) { | |
4071 | bottom = 0; /* zero length passwords are OK! :-) */ | |
4072 | top = 15; | |
4073 | } else { | |
4074 | bottom = pwlen & ~7; | |
4075 | top = bottom + 7; | |
4076 | } | |
4077 | ||
4078 | assert(pwlen >= bottom && pwlen <= top); | |
4079 | ||
4080 | randomstr = snewn(top + 1, char); | |
4081 | ||
4082 | for (i = bottom; i <= top; i++) { | |
4083 | if (i == pwlen) { | |
4084 | defer_packet(ssh, s->pwpkt_type, | |
4085 | PKTT_PASSWORD, PKT_STR, | |
4086 | s->cur_prompt->prompts[0]->result, | |
4087 | PKTT_OTHER, PKT_END); | |
4088 | } else { | |
4089 | for (j = 0; j < i; j++) { | |
4090 | do { | |
4091 | randomstr[j] = random_byte(); | |
4092 | } while (randomstr[j] == '\0'); | |
4093 | } | |
4094 | randomstr[i] = '\0'; | |
4095 | defer_packet(ssh, SSH1_MSG_IGNORE, | |
4096 | PKT_STR, randomstr, PKT_END); | |
4097 | } | |
4098 | } | |
4099 | logevent("Sending password with camouflage packets"); | |
4100 | ssh_pkt_defersend(ssh); | |
4101 | sfree(randomstr); | |
4102 | } | |
4103 | else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { | |
4104 | /* | |
4105 | * The server can't deal with SSH1_MSG_IGNORE | |
4106 | * but can deal with padded passwords, so we | |
4107 | * can use the secondary defence. | |
4108 | */ | |
4109 | char string[64]; | |
4110 | char *ss; | |
4111 | int len; | |
4112 | ||
4113 | len = strlen(s->cur_prompt->prompts[0]->result); | |
4114 | if (len < sizeof(string)) { | |
4115 | ss = string; | |
4116 | strcpy(string, s->cur_prompt->prompts[0]->result); | |
4117 | len++; /* cover the zero byte */ | |
4118 | while (len < sizeof(string)) { | |
4119 | string[len++] = (char) random_byte(); | |
4120 | } | |
4121 | } else { | |
4122 | ss = s->cur_prompt->prompts[0]->result; | |
4123 | } | |
4124 | logevent("Sending length-padded password"); | |
4125 | send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, | |
4126 | PKT_INT, len, PKT_DATA, ss, len, | |
4127 | PKTT_OTHER, PKT_END); | |
4128 | } else { | |
4129 | /* | |
4130 | * The server is believed unable to cope with | |
4131 | * any of our password camouflage methods. | |
4132 | */ | |
4133 | int len; | |
4134 | len = strlen(s->cur_prompt->prompts[0]->result); | |
4135 | logevent("Sending unpadded password"); | |
4136 | send_packet(ssh, s->pwpkt_type, | |
4137 | PKTT_PASSWORD, PKT_INT, len, | |
4138 | PKT_DATA, s->cur_prompt->prompts[0]->result, len, | |
4139 | PKTT_OTHER, PKT_END); | |
4140 | } | |
4141 | } else { | |
4142 | send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, | |
4143 | PKT_STR, s->cur_prompt->prompts[0]->result, | |
4144 | PKTT_OTHER, PKT_END); | |
4145 | } | |
4146 | logevent("Sent password"); | |
4147 | free_prompts(s->cur_prompt); | |
4148 | crWaitUntil(pktin); | |
4149 | if (pktin->type == SSH1_SMSG_FAILURE) { | |
4150 | if (flags & FLAG_VERBOSE) | |
4151 | c_write_str(ssh, "Access denied\r\n"); | |
4152 | logevent("Authentication refused"); | |
4153 | } else if (pktin->type != SSH1_SMSG_SUCCESS) { | |
4154 | bombout(("Strange packet received, type %d", pktin->type)); | |
4155 | crStop(0); | |
4156 | } | |
4157 | } | |
4158 | ||
4159 | /* Clear up */ | |
4160 | if (s->publickey_blob) { | |
4161 | sfree(s->publickey_blob); | |
4162 | sfree(s->publickey_comment); | |
4163 | } | |
4164 | ||
4165 | logevent("Authentication successful"); | |
4166 | ||
4167 | crFinish(1); | |
4168 | } | |
4169 | ||
4170 | void sshfwd_close(struct ssh_channel *c) | |
4171 | { | |
4172 | Ssh ssh = c->ssh; | |
4173 | ||
4174 | if (ssh->state == SSH_STATE_CLOSED) | |
4175 | return; | |
4176 | ||
4177 | if (!c->closes) { | |
4178 | /* | |
4179 | * If halfopen is true, we have sent | |
4180 | * CHANNEL_OPEN for this channel, but it hasn't even been | |
4181 | * acknowledged by the server. So we must set a close flag | |
4182 | * on it now, and then when the server acks the channel | |
4183 | * open, we can close it then. | |
4184 | */ | |
4185 | if (!c->halfopen) { | |
4186 | if (ssh->version == 1) { | |
4187 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, | |
4188 | PKT_END); | |
4189 | c->closes = 1; /* sent MSG_CLOSE */ | |
4190 | } else { | |
4191 | int bytes_to_send = bufchain_size(&c->v.v2.outbuffer); | |
4192 | if (bytes_to_send > 0) { | |
4193 | /* | |
4194 | * If we still have unsent data in our outgoing | |
4195 | * buffer for this channel, we can't actually | |
4196 | * initiate a close operation yet or that data | |
4197 | * will be lost. Instead, set the pending_close | |
4198 | * flag so that when we do clear the buffer | |
4199 | * we'll start closing the channel. | |
4200 | */ | |
4201 | char logmsg[160] = {'\0'}; | |
4202 | sprintf( | |
4203 | logmsg, | |
4204 | "Forwarded port pending to be closed : " | |
4205 | "%d bytes remaining", | |
4206 | bytes_to_send); | |
4207 | logevent(logmsg); | |
4208 | ||
4209 | c->pending_close = TRUE; | |
4210 | } else { | |
4211 | /* | |
4212 | * No locally buffered data, so we can send the | |
4213 | * close message immediately. | |
4214 | */ | |
4215 | struct Packet *pktout; | |
4216 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); | |
4217 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
4218 | ssh2_pkt_send(ssh, pktout); | |
4219 | c->closes = 1; /* sent MSG_CLOSE */ | |
4220 | logevent("Nothing left to send, closing channel"); | |
4221 | } | |
4222 | } | |
4223 | } | |
4224 | ||
4225 | if (c->type == CHAN_X11) { | |
4226 | c->u.x11.s = NULL; | |
4227 | logevent("Forwarded X11 connection terminated"); | |
4228 | } else if (c->type == CHAN_SOCKDATA || | |
4229 | c->type == CHAN_SOCKDATA_DORMANT) { | |
4230 | c->u.pfd.s = NULL; | |
4231 | logevent("Forwarded port closed"); | |
4232 | } | |
4233 | } | |
4234 | } | |
4235 | ||
4236 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) | |
4237 | { | |
4238 | Ssh ssh = c->ssh; | |
4239 | ||
4240 | if (ssh->state == SSH_STATE_CLOSED) | |
4241 | return 0; | |
4242 | ||
4243 | if (ssh->version == 1) { | |
4244 | send_packet(ssh, SSH1_MSG_CHANNEL_DATA, | |
4245 | PKT_INT, c->remoteid, | |
4246 | PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len, | |
4247 | PKTT_OTHER, PKT_END); | |
4248 | /* | |
4249 | * In SSH-1 we can return 0 here - implying that forwarded | |
4250 | * connections are never individually throttled - because | |
4251 | * the only circumstance that can cause throttling will be | |
4252 | * the whole SSH connection backing up, in which case | |
4253 | * _everything_ will be throttled as a whole. | |
4254 | */ | |
4255 | return 0; | |
4256 | } else { | |
4257 | ssh2_add_channel_data(c, buf, len); | |
4258 | return ssh2_try_send(c); | |
4259 | } | |
4260 | } | |
4261 | ||
4262 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) | |
4263 | { | |
4264 | Ssh ssh = c->ssh; | |
4265 | int buflimit; | |
4266 | ||
4267 | if (ssh->state == SSH_STATE_CLOSED) | |
4268 | return; | |
4269 | ||
4270 | if (ssh->version == 1) { | |
4271 | buflimit = SSH1_BUFFER_LIMIT; | |
4272 | } else { | |
4273 | buflimit = c->v.v2.locmaxwin; | |
4274 | ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0); | |
4275 | } | |
4276 | if (c->throttling_conn && bufsize <= buflimit) { | |
4277 | c->throttling_conn = 0; | |
4278 | ssh_throttle_conn(ssh, -1); | |
4279 | } | |
4280 | } | |
4281 | ||
4282 | static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) | |
4283 | { | |
4284 | struct queued_handler *qh = ssh->qhead; | |
4285 | ||
4286 | assert(qh != NULL); | |
4287 | ||
4288 | assert(pktin->type == qh->msg1 || pktin->type == qh->msg2); | |
4289 | ||
4290 | if (qh->msg1 > 0) { | |
4291 | assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler); | |
4292 | ssh->packet_dispatch[qh->msg1] = NULL; | |
4293 | } | |
4294 | if (qh->msg2 > 0) { | |
4295 | assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler); | |
4296 | ssh->packet_dispatch[qh->msg2] = NULL; | |
4297 | } | |
4298 | ||
4299 | if (qh->next) { | |
4300 | ssh->qhead = qh->next; | |
4301 | ||
4302 | if (ssh->qhead->msg1 > 0) { | |
4303 | assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL); | |
4304 | ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler; | |
4305 | } | |
4306 | if (ssh->qhead->msg2 > 0) { | |
4307 | assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL); | |
4308 | ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler; | |
4309 | } | |
4310 | } else { | |
4311 | ssh->qhead = ssh->qtail = NULL; | |
4312 | ssh->packet_dispatch[pktin->type] = NULL; | |
4313 | } | |
4314 | ||
4315 | qh->handler(ssh, pktin, qh->ctx); | |
4316 | ||
4317 | sfree(qh); | |
4318 | } | |
4319 | ||
4320 | static void ssh_queue_handler(Ssh ssh, int msg1, int msg2, | |
4321 | chandler_fn_t handler, void *ctx) | |
4322 | { | |
4323 | struct queued_handler *qh; | |
4324 | ||
4325 | qh = snew(struct queued_handler); | |
4326 | qh->msg1 = msg1; | |
4327 | qh->msg2 = msg2; | |
4328 | qh->handler = handler; | |
4329 | qh->ctx = ctx; | |
4330 | qh->next = NULL; | |
4331 | ||
4332 | if (ssh->qtail == NULL) { | |
4333 | ssh->qhead = qh; | |
4334 | ||
4335 | if (qh->msg1 > 0) { | |
4336 | assert(ssh->packet_dispatch[qh->msg1] == NULL); | |
4337 | ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler; | |
4338 | } | |
4339 | if (qh->msg2 > 0) { | |
4340 | assert(ssh->packet_dispatch[qh->msg2] == NULL); | |
4341 | ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler; | |
4342 | } | |
4343 | } else { | |
4344 | ssh->qtail->next = qh; | |
4345 | } | |
4346 | ssh->qtail = qh; | |
4347 | } | |
4348 | ||
4349 | static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) | |
4350 | { | |
4351 | struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx; | |
4352 | ||
4353 | if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS : | |
4354 | SSH2_MSG_REQUEST_SUCCESS)) { | |
4355 | logeventf(ssh, "Remote port forwarding from %s enabled", | |
4356 | pf->sportdesc); | |
4357 | } else { | |
4358 | logeventf(ssh, "Remote port forwarding from %s refused", | |
4359 | pf->sportdesc); | |
4360 | ||
4361 | rpf = del234(ssh->rportfwds, pf); | |
4362 | assert(rpf == pf); | |
4363 | pf->pfrec->remote = NULL; | |
4364 | free_rportfwd(pf); | |
4365 | } | |
4366 | } | |
4367 | ||
4368 | static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) | |
4369 | { | |
4370 | const char *portfwd_strptr = cfg->portfwd; | |
4371 | struct ssh_portfwd *epf; | |
4372 | int i; | |
4373 | ||
4374 | if (!ssh->portfwds) { | |
4375 | ssh->portfwds = newtree234(ssh_portcmp); | |
4376 | } else { | |
4377 | /* | |
4378 | * Go through the existing port forwardings and tag them | |
4379 | * with status==DESTROY. Any that we want to keep will be | |
4380 | * re-enabled (status==KEEP) as we go through the | |
4381 | * configuration and find out which bits are the same as | |
4382 | * they were before. | |
4383 | */ | |
4384 | struct ssh_portfwd *epf; | |
4385 | int i; | |
4386 | for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) | |
4387 | epf->status = DESTROY; | |
4388 | } | |
4389 | ||
4390 | while (*portfwd_strptr) { | |
4391 | char address_family, type; | |
4392 | int sport,dport,sserv,dserv; | |
4393 | char sports[256], dports[256], saddr[256], host[256]; | |
4394 | int n; | |
4395 | ||
4396 | address_family = 'A'; | |
4397 | type = 'L'; | |
4398 | if (*portfwd_strptr == 'A' || | |
4399 | *portfwd_strptr == '4' || | |
4400 | *portfwd_strptr == '6') | |
4401 | address_family = *portfwd_strptr++; | |
4402 | if (*portfwd_strptr == 'L' || | |
4403 | *portfwd_strptr == 'R' || | |
4404 | *portfwd_strptr == 'D') | |
4405 | type = *portfwd_strptr++; | |
4406 | ||
4407 | saddr[0] = '\0'; | |
4408 | ||
4409 | n = 0; | |
4410 | while (*portfwd_strptr && *portfwd_strptr != '\t') { | |
4411 | if (*portfwd_strptr == ':') { | |
4412 | /* | |
4413 | * We've seen a colon in the middle of the | |
4414 | * source port number. This means that | |
4415 | * everything we've seen until now is the | |
4416 | * source _address_, so we'll move it into | |
4417 | * saddr and start sports from the beginning | |
4418 | * again. | |
4419 | */ | |
4420 | portfwd_strptr++; | |
4421 | sports[n] = '\0'; | |
4422 | if (ssh->version == 1 && type == 'R') { | |
4423 | logeventf(ssh, "SSH-1 cannot handle remote source address " | |
4424 | "spec \"%s\"; ignoring", sports); | |
4425 | } else | |
4426 | strcpy(saddr, sports); | |
4427 | n = 0; | |
4428 | } | |
4429 | if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++; | |
4430 | } | |
4431 | sports[n] = 0; | |
4432 | if (type != 'D') { | |
4433 | if (*portfwd_strptr == '\t') | |
4434 | portfwd_strptr++; | |
4435 | n = 0; | |
4436 | while (*portfwd_strptr && *portfwd_strptr != ':') { | |
4437 | if (n < lenof(host)-1) host[n++] = *portfwd_strptr++; | |
4438 | } | |
4439 | host[n] = 0; | |
4440 | if (*portfwd_strptr == ':') | |
4441 | portfwd_strptr++; | |
4442 | n = 0; | |
4443 | while (*portfwd_strptr) { | |
4444 | if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++; | |
4445 | } | |
4446 | dports[n] = 0; | |
4447 | portfwd_strptr++; | |
4448 | dport = atoi(dports); | |
4449 | dserv = 0; | |
4450 | if (dport == 0) { | |
4451 | dserv = 1; | |
4452 | dport = net_service_lookup(dports); | |
4453 | if (!dport) { | |
4454 | logeventf(ssh, "Service lookup failed for destination" | |
4455 | " port \"%s\"", dports); | |
4456 | } | |
4457 | } | |
4458 | } else { | |
4459 | while (*portfwd_strptr) portfwd_strptr++; | |
4460 | host[0] = 0; | |
4461 | dports[0] = 0; | |
4462 | dport = dserv = -1; | |
4463 | portfwd_strptr++; /* eat the NUL and move to next one */ | |
4464 | } | |
4465 | sport = atoi(sports); | |
4466 | sserv = 0; | |
4467 | if (sport == 0) { | |
4468 | sserv = 1; | |
4469 | sport = net_service_lookup(sports); | |
4470 | if (!sport) { | |
4471 | logeventf(ssh, "Service lookup failed for source" | |
4472 | " port \"%s\"", sports); | |
4473 | } | |
4474 | } | |
4475 | if (sport && dport) { | |
4476 | /* Set up a description of the source port. */ | |
4477 | struct ssh_portfwd *pfrec, *epfrec; | |
4478 | ||
4479 | pfrec = snew(struct ssh_portfwd); | |
4480 | pfrec->type = type; | |
4481 | pfrec->saddr = *saddr ? dupstr(saddr) : NULL; | |
4482 | pfrec->sserv = sserv ? dupstr(sports) : NULL; | |
4483 | pfrec->sport = sport; | |
4484 | pfrec->daddr = *host ? dupstr(host) : NULL; | |
4485 | pfrec->dserv = dserv ? dupstr(dports) : NULL; | |
4486 | pfrec->dport = dport; | |
4487 | pfrec->local = NULL; | |
4488 | pfrec->remote = NULL; | |
4489 | pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 : | |
4490 | address_family == '6' ? ADDRTYPE_IPV6 : | |
4491 | ADDRTYPE_UNSPEC); | |
4492 | ||
4493 | epfrec = add234(ssh->portfwds, pfrec); | |
4494 | if (epfrec != pfrec) { | |
4495 | if (epfrec->status == DESTROY) { | |
4496 | /* | |
4497 | * We already have a port forwarding up and running | |
4498 | * with precisely these parameters. Hence, no need | |
4499 | * to do anything; simply re-tag the existing one | |
4500 | * as KEEP. | |
4501 | */ | |
4502 | epfrec->status = KEEP; | |
4503 | } | |
4504 | /* | |
4505 | * Anything else indicates that there was a duplicate | |
4506 | * in our input, which we'll silently ignore. | |
4507 | */ | |
4508 | free_portfwd(pfrec); | |
4509 | } else { | |
4510 | pfrec->status = CREATE; | |
4511 | } | |
4512 | } | |
4513 | } | |
4514 | ||
4515 | /* | |
4516 | * Now go through and destroy any port forwardings which were | |
4517 | * not re-enabled. | |
4518 | */ | |
4519 | for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) | |
4520 | if (epf->status == DESTROY) { | |
4521 | char *message; | |
4522 | ||
4523 | message = dupprintf("%s port forwarding from %s%s%d", | |
4524 | epf->type == 'L' ? "local" : | |
4525 | epf->type == 'R' ? "remote" : "dynamic", | |
4526 | epf->saddr ? epf->saddr : "", | |
4527 | epf->saddr ? ":" : "", | |
4528 | epf->sport); | |
4529 | ||
4530 | if (epf->type != 'D') { | |
4531 | char *msg2 = dupprintf("%s to %s:%d", message, | |
4532 | epf->daddr, epf->dport); | |
4533 | sfree(message); | |
4534 | message = msg2; | |
4535 | } | |
4536 | ||
4537 | logeventf(ssh, "Cancelling %s", message); | |
4538 | sfree(message); | |
4539 | ||
4540 | /* epf->remote or epf->local may be NULL if setting up a | |
4541 | * forwarding failed. */ | |
4542 | if (epf->remote) { | |
4543 | struct ssh_rportfwd *rpf = epf->remote; | |
4544 | struct Packet *pktout; | |
4545 | ||
4546 | /* | |
4547 | * Cancel the port forwarding at the server | |
4548 | * end. | |
4549 | */ | |
4550 | if (ssh->version == 1) { | |
4551 | /* | |
4552 | * We cannot cancel listening ports on the | |
4553 | * server side in SSH-1! There's no message | |
4554 | * to support it. Instead, we simply remove | |
4555 | * the rportfwd record from the local end | |
4556 | * so that any connections the server tries | |
4557 | * to make on it are rejected. | |
4558 | */ | |
4559 | } else { | |
4560 | pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); | |
4561 | ssh2_pkt_addstring(pktout, "cancel-tcpip-forward"); | |
4562 | ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */ | |
4563 | if (epf->saddr) { | |
4564 | ssh2_pkt_addstring(pktout, epf->saddr); | |
4565 | } else if (ssh->cfg.rport_acceptall) { | |
4566 | /* XXX: ssh->cfg.rport_acceptall may not represent | |
4567 | * what was used to open the original connection, | |
4568 | * since it's reconfigurable. */ | |
4569 | ssh2_pkt_addstring(pktout, "0.0.0.0"); | |
4570 | } else { | |
4571 | ssh2_pkt_addstring(pktout, "127.0.0.1"); | |
4572 | } | |
4573 | ssh2_pkt_adduint32(pktout, epf->sport); | |
4574 | ssh2_pkt_send(ssh, pktout); | |
4575 | } | |
4576 | ||
4577 | del234(ssh->rportfwds, rpf); | |
4578 | free_rportfwd(rpf); | |
4579 | } else if (epf->local) { | |
4580 | pfd_terminate(epf->local); | |
4581 | } | |
4582 | ||
4583 | delpos234(ssh->portfwds, i); | |
4584 | free_portfwd(epf); | |
4585 | i--; /* so we don't skip one in the list */ | |
4586 | } | |
4587 | ||
4588 | /* | |
4589 | * And finally, set up any new port forwardings (status==CREATE). | |
4590 | */ | |
4591 | for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) | |
4592 | if (epf->status == CREATE) { | |
4593 | char *sportdesc, *dportdesc; | |
4594 | sportdesc = dupprintf("%s%s%s%s%d%s", | |
4595 | epf->saddr ? epf->saddr : "", | |
4596 | epf->saddr ? ":" : "", | |
4597 | epf->sserv ? epf->sserv : "", | |
4598 | epf->sserv ? "(" : "", | |
4599 | epf->sport, | |
4600 | epf->sserv ? ")" : ""); | |
4601 | if (epf->type == 'D') { | |
4602 | dportdesc = NULL; | |
4603 | } else { | |
4604 | dportdesc = dupprintf("%s:%s%s%d%s", | |
4605 | epf->daddr, | |
4606 | epf->dserv ? epf->dserv : "", | |
4607 | epf->dserv ? "(" : "", | |
4608 | epf->dport, | |
4609 | epf->dserv ? ")" : ""); | |
4610 | } | |
4611 | ||
4612 | if (epf->type == 'L') { | |
4613 | const char *err = pfd_addforward(epf->daddr, epf->dport, | |
4614 | epf->saddr, epf->sport, | |
4615 | ssh, cfg, | |
4616 | &epf->local, | |
4617 | epf->addressfamily); | |
4618 | ||
4619 | logeventf(ssh, "Local %sport %s forwarding to %s%s%s", | |
4620 | epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : | |
4621 | epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", | |
4622 | sportdesc, dportdesc, | |
4623 | err ? " failed: " : "", err ? err : ""); | |
4624 | } else if (epf->type == 'D') { | |
4625 | const char *err = pfd_addforward(NULL, -1, | |
4626 | epf->saddr, epf->sport, | |
4627 | ssh, cfg, | |
4628 | &epf->local, | |
4629 | epf->addressfamily); | |
4630 | ||
4631 | logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s", | |
4632 | epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : | |
4633 | epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", | |
4634 | sportdesc, | |
4635 | err ? " failed: " : "", err ? err : ""); | |
4636 | } else { | |
4637 | struct ssh_rportfwd *pf; | |
4638 | ||
4639 | /* | |
4640 | * Ensure the remote port forwardings tree exists. | |
4641 | */ | |
4642 | if (!ssh->rportfwds) { | |
4643 | if (ssh->version == 1) | |
4644 | ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); | |
4645 | else | |
4646 | ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); | |
4647 | } | |
4648 | ||
4649 | pf = snew(struct ssh_rportfwd); | |
4650 | strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1); | |
4651 | pf->dhost[lenof(pf->dhost)-1] = '\0'; | |
4652 | pf->dport = epf->dport; | |
4653 | pf->sport = epf->sport; | |
4654 | if (add234(ssh->rportfwds, pf) != pf) { | |
4655 | logeventf(ssh, "Duplicate remote port forwarding to %s:%d", | |
4656 | epf->daddr, epf->dport); | |
4657 | sfree(pf); | |
4658 | } else { | |
4659 | logeventf(ssh, "Requesting remote port %s" | |
4660 | " forward to %s", sportdesc, dportdesc); | |
4661 | ||
4662 | pf->sportdesc = sportdesc; | |
4663 | sportdesc = NULL; | |
4664 | epf->remote = pf; | |
4665 | pf->pfrec = epf; | |
4666 | ||
4667 | if (ssh->version == 1) { | |
4668 | send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, | |
4669 | PKT_INT, epf->sport, | |
4670 | PKT_STR, epf->daddr, | |
4671 | PKT_INT, epf->dport, | |
4672 | PKT_END); | |
4673 | ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS, | |
4674 | SSH1_SMSG_FAILURE, | |
4675 | ssh_rportfwd_succfail, pf); | |
4676 | } else { | |
4677 | struct Packet *pktout; | |
4678 | pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); | |
4679 | ssh2_pkt_addstring(pktout, "tcpip-forward"); | |
4680 | ssh2_pkt_addbool(pktout, 1);/* want reply */ | |
4681 | if (epf->saddr) { | |
4682 | ssh2_pkt_addstring(pktout, epf->saddr); | |
4683 | } else if (cfg->rport_acceptall) { | |
4684 | ssh2_pkt_addstring(pktout, "0.0.0.0"); | |
4685 | } else { | |
4686 | ssh2_pkt_addstring(pktout, "127.0.0.1"); | |
4687 | } | |
4688 | ssh2_pkt_adduint32(pktout, epf->sport); | |
4689 | ssh2_pkt_send(ssh, pktout); | |
4690 | ||
4691 | ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, | |
4692 | SSH2_MSG_REQUEST_FAILURE, | |
4693 | ssh_rportfwd_succfail, pf); | |
4694 | } | |
4695 | } | |
4696 | } | |
4697 | sfree(sportdesc); | |
4698 | sfree(dportdesc); | |
4699 | } | |
4700 | } | |
4701 | ||
4702 | static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin) | |
4703 | { | |
4704 | char *string; | |
4705 | int stringlen, bufsize; | |
4706 | ||
4707 | ssh_pkt_getstring(pktin, &string, &stringlen); | |
4708 | if (string == NULL) { | |
4709 | bombout(("Incoming terminal data packet was badly formed")); | |
4710 | return; | |
4711 | } | |
4712 | ||
4713 | bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA, | |
4714 | string, stringlen); | |
4715 | if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { | |
4716 | ssh->v1_stdout_throttling = 1; | |
4717 | ssh_throttle_conn(ssh, +1); | |
4718 | } | |
4719 | } | |
4720 | ||
4721 | static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) | |
4722 | { | |
4723 | /* Remote side is trying to open a channel to talk to our | |
4724 | * X-Server. Give them back a local channel number. */ | |
4725 | struct ssh_channel *c; | |
4726 | int remoteid = ssh_pkt_getuint32(pktin); | |
4727 | ||
4728 | logevent("Received X11 connect request"); | |
4729 | /* Refuse if X11 forwarding is disabled. */ | |
4730 | if (!ssh->X11_fwd_enabled) { | |
4731 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, | |
4732 | PKT_INT, remoteid, PKT_END); | |
4733 | logevent("Rejected X11 connect request"); | |
4734 | } else { | |
4735 | c = snew(struct ssh_channel); | |
4736 | c->ssh = ssh; | |
4737 | ||
4738 | if (x11_init(&c->u.x11.s, ssh->x11disp, c, | |
4739 | NULL, -1, &ssh->cfg) != NULL) { | |
4740 | logevent("Opening X11 forward connection failed"); | |
4741 | sfree(c); | |
4742 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, | |
4743 | PKT_INT, remoteid, PKT_END); | |
4744 | } else { | |
4745 | logevent | |
4746 | ("Opening X11 forward connection succeeded"); | |
4747 | c->remoteid = remoteid; | |
4748 | c->halfopen = FALSE; | |
4749 | c->localid = alloc_channel_id(ssh); | |
4750 | c->closes = 0; | |
4751 | c->pending_close = FALSE; | |
4752 | c->throttling_conn = 0; | |
4753 | c->type = CHAN_X11; /* identify channel type */ | |
4754 | add234(ssh->channels, c); | |
4755 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, | |
4756 | PKT_INT, c->remoteid, PKT_INT, | |
4757 | c->localid, PKT_END); | |
4758 | logevent("Opened X11 forward channel"); | |
4759 | } | |
4760 | } | |
4761 | } | |
4762 | ||
4763 | static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) | |
4764 | { | |
4765 | /* Remote side is trying to open a channel to talk to our | |
4766 | * agent. Give them back a local channel number. */ | |
4767 | struct ssh_channel *c; | |
4768 | int remoteid = ssh_pkt_getuint32(pktin); | |
4769 | ||
4770 | /* Refuse if agent forwarding is disabled. */ | |
4771 | if (!ssh->agentfwd_enabled) { | |
4772 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, | |
4773 | PKT_INT, remoteid, PKT_END); | |
4774 | } else { | |
4775 | c = snew(struct ssh_channel); | |
4776 | c->ssh = ssh; | |
4777 | c->remoteid = remoteid; | |
4778 | c->halfopen = FALSE; | |
4779 | c->localid = alloc_channel_id(ssh); | |
4780 | c->closes = 0; | |
4781 | c->pending_close = FALSE; | |
4782 | c->throttling_conn = 0; | |
4783 | c->type = CHAN_AGENT; /* identify channel type */ | |
4784 | c->u.a.lensofar = 0; | |
4785 | add234(ssh->channels, c); | |
4786 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, | |
4787 | PKT_INT, c->remoteid, PKT_INT, c->localid, | |
4788 | PKT_END); | |
4789 | } | |
4790 | } | |
4791 | ||
4792 | static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) | |
4793 | { | |
4794 | /* Remote side is trying to open a channel to talk to a | |
4795 | * forwarded port. Give them back a local channel number. */ | |
4796 | struct ssh_channel *c; | |
4797 | struct ssh_rportfwd pf, *pfp; | |
4798 | int remoteid; | |
4799 | int hostsize, port; | |
4800 | char *host; | |
4801 | const char *e; | |
4802 | c = snew(struct ssh_channel); | |
4803 | c->ssh = ssh; | |
4804 | ||
4805 | remoteid = ssh_pkt_getuint32(pktin); | |
4806 | ssh_pkt_getstring(pktin, &host, &hostsize); | |
4807 | port = ssh_pkt_getuint32(pktin); | |
4808 | ||
4809 | if (hostsize >= lenof(pf.dhost)) | |
4810 | hostsize = lenof(pf.dhost)-1; | |
4811 | memcpy(pf.dhost, host, hostsize); | |
4812 | pf.dhost[hostsize] = '\0'; | |
4813 | pf.dport = port; | |
4814 | pfp = find234(ssh->rportfwds, &pf, NULL); | |
4815 | ||
4816 | if (pfp == NULL) { | |
4817 | logeventf(ssh, "Rejected remote port open request for %s:%d", | |
4818 | pf.dhost, port); | |
4819 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, | |
4820 | PKT_INT, remoteid, PKT_END); | |
4821 | } else { | |
4822 | logeventf(ssh, "Received remote port open request for %s:%d", | |
4823 | pf.dhost, port); | |
4824 | e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port, | |
4825 | c, &ssh->cfg, pfp->pfrec->addressfamily); | |
4826 | if (e != NULL) { | |
4827 | logeventf(ssh, "Port open failed: %s", e); | |
4828 | sfree(c); | |
4829 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, | |
4830 | PKT_INT, remoteid, PKT_END); | |
4831 | } else { | |
4832 | c->remoteid = remoteid; | |
4833 | c->halfopen = FALSE; | |
4834 | c->localid = alloc_channel_id(ssh); | |
4835 | c->closes = 0; | |
4836 | c->pending_close = FALSE; | |
4837 | c->throttling_conn = 0; | |
4838 | c->type = CHAN_SOCKDATA; /* identify channel type */ | |
4839 | add234(ssh->channels, c); | |
4840 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, | |
4841 | PKT_INT, c->remoteid, PKT_INT, | |
4842 | c->localid, PKT_END); | |
4843 | logevent("Forwarded port opened successfully"); | |
4844 | } | |
4845 | } | |
4846 | } | |
4847 | ||
4848 | static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) | |
4849 | { | |
4850 | unsigned int remoteid = ssh_pkt_getuint32(pktin); | |
4851 | unsigned int localid = ssh_pkt_getuint32(pktin); | |
4852 | struct ssh_channel *c; | |
4853 | ||
4854 | c = find234(ssh->channels, &remoteid, ssh_channelfind); | |
4855 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { | |
4856 | c->remoteid = localid; | |
4857 | c->halfopen = FALSE; | |
4858 | c->type = CHAN_SOCKDATA; | |
4859 | c->throttling_conn = 0; | |
4860 | pfd_confirm(c->u.pfd.s); | |
4861 | } | |
4862 | ||
4863 | if (c && c->closes) { | |
4864 | /* | |
4865 | * We have a pending close on this channel, | |
4866 | * which we decided on before the server acked | |
4867 | * the channel open. So now we know the | |
4868 | * remoteid, we can close it again. | |
4869 | */ | |
4870 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, | |
4871 | PKT_INT, c->remoteid, PKT_END); | |
4872 | } | |
4873 | } | |
4874 | ||
4875 | static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) | |
4876 | { | |
4877 | unsigned int remoteid = ssh_pkt_getuint32(pktin); | |
4878 | struct ssh_channel *c; | |
4879 | ||
4880 | c = find234(ssh->channels, &remoteid, ssh_channelfind); | |
4881 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { | |
4882 | logevent("Forwarded connection refused by server"); | |
4883 | pfd_close(c->u.pfd.s); | |
4884 | del234(ssh->channels, c); | |
4885 | sfree(c); | |
4886 | } | |
4887 | } | |
4888 | ||
4889 | static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) | |
4890 | { | |
4891 | /* Remote side closes a channel. */ | |
4892 | unsigned i = ssh_pkt_getuint32(pktin); | |
4893 | struct ssh_channel *c; | |
4894 | c = find234(ssh->channels, &i, ssh_channelfind); | |
4895 | if (c && !c->halfopen) { | |
4896 | int closetype; | |
4897 | closetype = | |
4898 | (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); | |
4899 | ||
4900 | if ((c->closes == 0) && (c->type == CHAN_X11)) { | |
4901 | logevent("Forwarded X11 connection terminated"); | |
4902 | assert(c->u.x11.s != NULL); | |
4903 | x11_close(c->u.x11.s); | |
4904 | c->u.x11.s = NULL; | |
4905 | } | |
4906 | if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { | |
4907 | logevent("Forwarded port closed"); | |
4908 | assert(c->u.pfd.s != NULL); | |
4909 | pfd_close(c->u.pfd.s); | |
4910 | c->u.pfd.s = NULL; | |
4911 | } | |
4912 | ||
4913 | c->closes |= (closetype << 2); /* seen this message */ | |
4914 | if (!(c->closes & closetype)) { | |
4915 | send_packet(ssh, pktin->type, PKT_INT, c->remoteid, | |
4916 | PKT_END); | |
4917 | c->closes |= closetype; /* sent it too */ | |
4918 | } | |
4919 | ||
4920 | if (c->closes == 15) { | |
4921 | del234(ssh->channels, c); | |
4922 | sfree(c); | |
4923 | } | |
4924 | } else { | |
4925 | bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", | |
4926 | pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" : | |
4927 | "_CONFIRMATION", c ? "half-open" : "nonexistent", | |
4928 | i)); | |
4929 | } | |
4930 | } | |
4931 | ||
4932 | static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) | |
4933 | { | |
4934 | /* Data sent down one of our channels. */ | |
4935 | int i = ssh_pkt_getuint32(pktin); | |
4936 | char *p; | |
4937 | int len; | |
4938 | struct ssh_channel *c; | |
4939 | ||
4940 | ssh_pkt_getstring(pktin, &p, &len); | |
4941 | ||
4942 | c = find234(ssh->channels, &i, ssh_channelfind); | |
4943 | if (c) { | |
4944 | int bufsize = 0; | |
4945 | switch (c->type) { | |
4946 | case CHAN_X11: | |
4947 | bufsize = x11_send(c->u.x11.s, p, len); | |
4948 | break; | |
4949 | case CHAN_SOCKDATA: | |
4950 | bufsize = pfd_send(c->u.pfd.s, p, len); | |
4951 | break; | |
4952 | case CHAN_AGENT: | |
4953 | /* Data for an agent message. Buffer it. */ | |
4954 | while (len > 0) { | |
4955 | if (c->u.a.lensofar < 4) { | |
4956 | unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len); | |
4957 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, | |
4958 | l); | |
4959 | p += l; | |
4960 | len -= l; | |
4961 | c->u.a.lensofar += l; | |
4962 | } | |
4963 | if (c->u.a.lensofar == 4) { | |
4964 | c->u.a.totallen = | |
4965 | 4 + GET_32BIT(c->u.a.msglen); | |
4966 | c->u.a.message = snewn(c->u.a.totallen, | |
4967 | unsigned char); | |
4968 | memcpy(c->u.a.message, c->u.a.msglen, 4); | |
4969 | } | |
4970 | if (c->u.a.lensofar >= 4 && len > 0) { | |
4971 | unsigned int l = | |
4972 | min(c->u.a.totallen - c->u.a.lensofar, | |
4973 | (unsigned)len); | |
4974 | memcpy(c->u.a.message + c->u.a.lensofar, p, | |
4975 | l); | |
4976 | p += l; | |
4977 | len -= l; | |
4978 | c->u.a.lensofar += l; | |
4979 | } | |
4980 | if (c->u.a.lensofar == c->u.a.totallen) { | |
4981 | void *reply; | |
4982 | int replylen; | |
4983 | if (agent_query(c->u.a.message, | |
4984 | c->u.a.totallen, | |
4985 | &reply, &replylen, | |
4986 | ssh_agentf_callback, c)) | |
4987 | ssh_agentf_callback(c, reply, replylen); | |
4988 | sfree(c->u.a.message); | |
4989 | c->u.a.lensofar = 0; | |
4990 | } | |
4991 | } | |
4992 | bufsize = 0; /* agent channels never back up */ | |
4993 | break; | |
4994 | } | |
4995 | if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) { | |
4996 | c->throttling_conn = 1; | |
4997 | ssh_throttle_conn(ssh, +1); | |
4998 | } | |
4999 | } | |
5000 | } | |
5001 | ||
5002 | static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) | |
5003 | { | |
5004 | ssh->exitcode = ssh_pkt_getuint32(pktin); | |
5005 | logeventf(ssh, "Server sent command exit status %d", ssh->exitcode); | |
5006 | send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); | |
5007 | /* | |
5008 | * In case `helpful' firewalls or proxies tack | |
5009 | * extra human-readable text on the end of the | |
5010 | * session which we might mistake for another | |
5011 | * encrypted packet, we close the session once | |
5012 | * we've sent EXIT_CONFIRMATION. | |
5013 | */ | |
5014 | ssh_disconnect(ssh, NULL, NULL, 0, TRUE); | |
5015 | } | |
5016 | ||
5017 | /* Helper function to deal with sending tty modes for REQUEST_PTY */ | |
5018 | static void ssh1_send_ttymode(void *data, char *mode, char *val) | |
5019 | { | |
5020 | struct Packet *pktout = (struct Packet *)data; | |
5021 | int i = 0; | |
5022 | unsigned int arg = 0; | |
5023 | while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; | |
5024 | if (i == lenof(ssh_ttymodes)) return; | |
5025 | switch (ssh_ttymodes[i].type) { | |
5026 | case TTY_OP_CHAR: | |
5027 | arg = ssh_tty_parse_specchar(val); | |
5028 | break; | |
5029 | case TTY_OP_BOOL: | |
5030 | arg = ssh_tty_parse_boolean(val); | |
5031 | break; | |
5032 | } | |
5033 | ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); | |
5034 | ssh2_pkt_addbyte(pktout, arg); | |
5035 | } | |
5036 | ||
5037 | ||
5038 | static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, | |
5039 | struct Packet *pktin) | |
5040 | { | |
5041 | crBegin(ssh->do_ssh1_connection_crstate); | |
5042 | ||
5043 | ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] = | |
5044 | ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] = | |
5045 | ssh1_smsg_stdout_stderr_data; | |
5046 | ||
5047 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] = | |
5048 | ssh1_msg_channel_open_confirmation; | |
5049 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] = | |
5050 | ssh1_msg_channel_open_failure; | |
5051 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] = | |
5052 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] = | |
5053 | ssh1_msg_channel_close; | |
5054 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data; | |
5055 | ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status; | |
5056 | ||
5057 | if (ssh->cfg.agentfwd && agent_exists()) { | |
5058 | logevent("Requesting agent forwarding"); | |
5059 | send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); | |
5060 | do { | |
5061 | crReturnV; | |
5062 | } while (!pktin); | |
5063 | if (pktin->type != SSH1_SMSG_SUCCESS | |
5064 | && pktin->type != SSH1_SMSG_FAILURE) { | |
5065 | bombout(("Protocol confusion")); | |
5066 | crStopV; | |
5067 | } else if (pktin->type == SSH1_SMSG_FAILURE) { | |
5068 | logevent("Agent forwarding refused"); | |
5069 | } else { | |
5070 | logevent("Agent forwarding enabled"); | |
5071 | ssh->agentfwd_enabled = TRUE; | |
5072 | ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open; | |
5073 | } | |
5074 | } | |
5075 | ||
5076 | if (ssh->cfg.x11_forward && | |
5077 | (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display, | |
5078 | ssh->cfg.x11_auth, &ssh->cfg))) { | |
5079 | logevent("Requesting X11 forwarding"); | |
5080 | /* | |
5081 | * Note that while we blank the X authentication data here, we don't | |
5082 | * take any special action to blank the start of an X11 channel, | |
5083 | * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection | |
5084 | * without having session blanking enabled is likely to leak your | |
5085 | * cookie into the log. | |
5086 | */ | |
5087 | if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { | |
5088 | send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, | |
5089 | PKT_STR, ssh->x11disp->remoteauthprotoname, | |
5090 | PKTT_PASSWORD, | |
5091 | PKT_STR, ssh->x11disp->remoteauthdatastring, | |
5092 | PKTT_OTHER, | |
5093 | PKT_INT, ssh->x11disp->screennum, | |
5094 | PKT_END); | |
5095 | } else { | |
5096 | send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, | |
5097 | PKT_STR, ssh->x11disp->remoteauthprotoname, | |
5098 | PKTT_PASSWORD, | |
5099 | PKT_STR, ssh->x11disp->remoteauthdatastring, | |
5100 | PKTT_OTHER, | |
5101 | PKT_END); | |
5102 | } | |
5103 | do { | |
5104 | crReturnV; | |
5105 | } while (!pktin); | |
5106 | if (pktin->type != SSH1_SMSG_SUCCESS | |
5107 | && pktin->type != SSH1_SMSG_FAILURE) { | |
5108 | bombout(("Protocol confusion")); | |
5109 | crStopV; | |
5110 | } else if (pktin->type == SSH1_SMSG_FAILURE) { | |
5111 | logevent("X11 forwarding refused"); | |
5112 | } else { | |
5113 | logevent("X11 forwarding enabled"); | |
5114 | ssh->X11_fwd_enabled = TRUE; | |
5115 | ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open; | |
5116 | } | |
5117 | } | |
5118 | ||
5119 | ssh_setup_portfwd(ssh, &ssh->cfg); | |
5120 | ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open; | |
5121 | ||
5122 | if (!ssh->cfg.nopty) { | |
5123 | struct Packet *pkt; | |
5124 | /* Unpick the terminal-speed string. */ | |
5125 | /* XXX perhaps we should allow no speeds to be sent. */ | |
5126 | ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ | |
5127 | sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed); | |
5128 | /* Send the pty request. */ | |
5129 | pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY); | |
5130 | ssh_pkt_addstring(pkt, ssh->cfg.termtype); | |
5131 | ssh_pkt_adduint32(pkt, ssh->term_height); | |
5132 | ssh_pkt_adduint32(pkt, ssh->term_width); | |
5133 | ssh_pkt_adduint32(pkt, 0); /* width in pixels */ | |
5134 | ssh_pkt_adduint32(pkt, 0); /* height in pixels */ | |
5135 | parse_ttymodes(ssh, ssh->cfg.ttymodes, | |
5136 | ssh1_send_ttymode, (void *)pkt); | |
5137 | ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED); | |
5138 | ssh_pkt_adduint32(pkt, ssh->ispeed); | |
5139 | ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED); | |
5140 | ssh_pkt_adduint32(pkt, ssh->ospeed); | |
5141 | ssh_pkt_addbyte(pkt, SSH_TTY_OP_END); | |
5142 | s_wrpkt(ssh, pkt); | |
5143 | ssh->state = SSH_STATE_INTERMED; | |
5144 | do { | |
5145 | crReturnV; | |
5146 | } while (!pktin); | |
5147 | if (pktin->type != SSH1_SMSG_SUCCESS | |
5148 | && pktin->type != SSH1_SMSG_FAILURE) { | |
5149 | bombout(("Protocol confusion")); | |
5150 | crStopV; | |
5151 | } else if (pktin->type == SSH1_SMSG_FAILURE) { | |
5152 | c_write_str(ssh, "Server refused to allocate pty\r\n"); | |
5153 | ssh->editing = ssh->echoing = 1; | |
5154 | } | |
5155 | logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", | |
5156 | ssh->ospeed, ssh->ispeed); | |
5157 | } else { | |
5158 | ssh->editing = ssh->echoing = 1; | |
5159 | } | |
5160 | ||
5161 | if (ssh->cfg.compression) { | |
5162 | send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); | |
5163 | do { | |
5164 | crReturnV; | |
5165 | } while (!pktin); | |
5166 | if (pktin->type != SSH1_SMSG_SUCCESS | |
5167 | && pktin->type != SSH1_SMSG_FAILURE) { | |
5168 | bombout(("Protocol confusion")); | |
5169 | crStopV; | |
5170 | } else if (pktin->type == SSH1_SMSG_FAILURE) { | |
5171 | c_write_str(ssh, "Server refused to compress\r\n"); | |
5172 | } | |
5173 | logevent("Started compression"); | |
5174 | ssh->v1_compressing = TRUE; | |
5175 | ssh->cs_comp_ctx = zlib_compress_init(); | |
5176 | logevent("Initialised zlib (RFC1950) compression"); | |
5177 | ssh->sc_comp_ctx = zlib_decompress_init(); | |
5178 | logevent("Initialised zlib (RFC1950) decompression"); | |
5179 | } | |
5180 | ||
5181 | /* | |
5182 | * Start the shell or command. | |
5183 | * | |
5184 | * Special case: if the first-choice command is an SSH-2 | |
5185 | * subsystem (hence not usable here) and the second choice | |
5186 | * exists, we fall straight back to that. | |
5187 | */ | |
5188 | { | |
5189 | char *cmd = ssh->cfg.remote_cmd_ptr; | |
5190 | ||
5191 | if (!cmd) cmd = ssh->cfg.remote_cmd; | |
5192 | ||
5193 | if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) { | |
5194 | cmd = ssh->cfg.remote_cmd_ptr2; | |
5195 | ssh->fallback_cmd = TRUE; | |
5196 | } | |
5197 | if (*cmd) | |
5198 | send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); | |
5199 | else | |
5200 | send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END); | |
5201 | logevent("Started session"); | |
5202 | } | |
5203 | ||
5204 | ssh->state = SSH_STATE_SESSION; | |
5205 | if (ssh->size_needed) | |
5206 | ssh_size(ssh, ssh->term_width, ssh->term_height); | |
5207 | if (ssh->eof_needed) | |
5208 | ssh_special(ssh, TS_EOF); | |
5209 | ||
5210 | if (ssh->ldisc) | |
5211 | ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ | |
5212 | ssh->send_ok = 1; | |
5213 | ssh->channels = newtree234(ssh_channelcmp); | |
5214 | while (1) { | |
5215 | ||
5216 | /* | |
5217 | * By this point, most incoming packets are already being | |
5218 | * handled by the dispatch table, and we need only pay | |
5219 | * attention to the unusual ones. | |
5220 | */ | |
5221 | ||
5222 | crReturnV; | |
5223 | if (pktin) { | |
5224 | if (pktin->type == SSH1_SMSG_SUCCESS) { | |
5225 | /* may be from EXEC_SHELL on some servers */ | |
5226 | } else if (pktin->type == SSH1_SMSG_FAILURE) { | |
5227 | /* may be from EXEC_SHELL on some servers | |
5228 | * if no pty is available or in other odd cases. Ignore */ | |
5229 | } else { | |
5230 | bombout(("Strange packet received: type %d", pktin->type)); | |
5231 | crStopV; | |
5232 | } | |
5233 | } else { | |
5234 | while (inlen > 0) { | |
5235 | int len = min(inlen, 512); | |
5236 | send_packet(ssh, SSH1_CMSG_STDIN_DATA, | |
5237 | PKT_INT, len, PKTT_DATA, PKT_DATA, in, len, | |
5238 | PKTT_OTHER, PKT_END); | |
5239 | in += len; | |
5240 | inlen -= len; | |
5241 | } | |
5242 | } | |
5243 | } | |
5244 | ||
5245 | crFinishV; | |
5246 | } | |
5247 | ||
5248 | /* | |
5249 | * Handle the top-level SSH-2 protocol. | |
5250 | */ | |
5251 | static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) | |
5252 | { | |
5253 | char *msg; | |
5254 | int msglen; | |
5255 | ||
5256 | ssh_pkt_getstring(pktin, &msg, &msglen); | |
5257 | logeventf(ssh, "Remote debug message: %.*s", msglen, msg); | |
5258 | } | |
5259 | ||
5260 | static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) | |
5261 | { | |
5262 | /* log reason code in disconnect message */ | |
5263 | char *msg; | |
5264 | int msglen; | |
5265 | ||
5266 | ssh_pkt_getstring(pktin, &msg, &msglen); | |
5267 | bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); | |
5268 | } | |
5269 | ||
5270 | static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) | |
5271 | { | |
5272 | /* Do nothing, because we're ignoring it! Duhh. */ | |
5273 | } | |
5274 | ||
5275 | static void ssh1_protocol_setup(Ssh ssh) | |
5276 | { | |
5277 | int i; | |
5278 | ||
5279 | /* | |
5280 | * Most messages are handled by the coroutines. | |
5281 | */ | |
5282 | for (i = 0; i < 256; i++) | |
5283 | ssh->packet_dispatch[i] = NULL; | |
5284 | ||
5285 | /* | |
5286 | * These special message types we install handlers for. | |
5287 | */ | |
5288 | ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect; | |
5289 | ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore; | |
5290 | ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; | |
5291 | } | |
5292 | ||
5293 | static void ssh1_protocol(Ssh ssh, void *vin, int inlen, | |
5294 | struct Packet *pktin) | |
5295 | { | |
5296 | unsigned char *in=(unsigned char*)vin; | |
5297 | if (ssh->state == SSH_STATE_CLOSED) | |
5298 | return; | |
5299 | ||
5300 | if (pktin && ssh->packet_dispatch[pktin->type]) { | |
5301 | ssh->packet_dispatch[pktin->type](ssh, pktin); | |
5302 | return; | |
5303 | } | |
5304 | ||
5305 | if (!ssh->protocol_initial_phase_done) { | |
5306 | if (do_ssh1_login(ssh, in, inlen, pktin)) | |
5307 | ssh->protocol_initial_phase_done = TRUE; | |
5308 | else | |
5309 | return; | |
5310 | } | |
5311 | ||
5312 | do_ssh1_connection(ssh, in, inlen, pktin); | |
5313 | } | |
5314 | ||
5315 | /* | |
5316 | * Utility routine for decoding comma-separated strings in KEXINIT. | |
5317 | */ | |
5318 | static int in_commasep_string(char *needle, char *haystack, int haylen) | |
5319 | { | |
5320 | int needlen; | |
5321 | if (!needle || !haystack) /* protect against null pointers */ | |
5322 | return 0; | |
5323 | needlen = strlen(needle); | |
5324 | while (1) { | |
5325 | /* | |
5326 | * Is it at the start of the string? | |
5327 | */ | |
5328 | if (haylen >= needlen && /* haystack is long enough */ | |
5329 | !memcmp(needle, haystack, needlen) && /* initial match */ | |
5330 | (haylen == needlen || haystack[needlen] == ',') | |
5331 | /* either , or EOS follows */ | |
5332 | ) | |
5333 | return 1; | |
5334 | /* | |
5335 | * If not, search for the next comma and resume after that. | |
5336 | * If no comma found, terminate. | |
5337 | */ | |
5338 | while (haylen > 0 && *haystack != ',') | |
5339 | haylen--, haystack++; | |
5340 | if (haylen == 0) | |
5341 | return 0; | |
5342 | haylen--, haystack++; /* skip over comma itself */ | |
5343 | } | |
5344 | } | |
5345 | ||
5346 | /* | |
5347 | * Similar routine for checking whether we have the first string in a list. | |
5348 | */ | |
5349 | static int first_in_commasep_string(char *needle, char *haystack, int haylen) | |
5350 | { | |
5351 | int needlen; | |
5352 | if (!needle || !haystack) /* protect against null pointers */ | |
5353 | return 0; | |
5354 | needlen = strlen(needle); | |
5355 | /* | |
5356 | * Is it at the start of the string? | |
5357 | */ | |
5358 | if (haylen >= needlen && /* haystack is long enough */ | |
5359 | !memcmp(needle, haystack, needlen) && /* initial match */ | |
5360 | (haylen == needlen || haystack[needlen] == ',') | |
5361 | /* either , or EOS follows */ | |
5362 | ) | |
5363 | return 1; | |
5364 | return 0; | |
5365 | } | |
5366 | ||
5367 | ||
5368 | /* | |
5369 | * SSH-2 key creation method. | |
5370 | * (Currently assumes 2 lots of any hash are sufficient to generate | |
5371 | * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.) | |
5372 | */ | |
5373 | #define SSH2_MKKEY_ITERS (2) | |
5374 | static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, | |
5375 | unsigned char *keyspace) | |
5376 | { | |
5377 | const struct ssh_hash *h = ssh->kex->hash; | |
5378 | void *s; | |
5379 | /* First hlen bytes. */ | |
5380 | s = h->init(); | |
5381 | if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) | |
5382 | hash_mpint(h, s, K); | |
5383 | h->bytes(s, H, h->hlen); | |
5384 | h->bytes(s, &chr, 1); | |
5385 | h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len); | |
5386 | h->final(s, keyspace); | |
5387 | /* Next hlen bytes. */ | |
5388 | s = h->init(); | |
5389 | if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) | |
5390 | hash_mpint(h, s, K); | |
5391 | h->bytes(s, H, h->hlen); | |
5392 | h->bytes(s, keyspace, h->hlen); | |
5393 | h->final(s, keyspace + h->hlen); | |
5394 | } | |
5395 | ||
5396 | /* | |
5397 | * Handle the SSH-2 transport layer. | |
5398 | */ | |
5399 | static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, | |
5400 | struct Packet *pktin) | |
5401 | { | |
5402 | unsigned char *in = (unsigned char *)vin; | |
5403 | struct do_ssh2_transport_state { | |
5404 | int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; | |
5405 | Bignum p, g, e, f, K; | |
5406 | void *our_kexinit; | |
5407 | int our_kexinitlen; | |
5408 | int kex_init_value, kex_reply_value; | |
5409 | const struct ssh_mac **maclist; | |
5410 | int nmacs; | |
5411 | const struct ssh2_cipher *cscipher_tobe; | |
5412 | const struct ssh2_cipher *sccipher_tobe; | |
5413 | const struct ssh_mac *csmac_tobe; | |
5414 | const struct ssh_mac *scmac_tobe; | |
5415 | const struct ssh_compress *cscomp_tobe; | |
5416 | const struct ssh_compress *sccomp_tobe; | |
5417 | char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint; | |
5418 | int hostkeylen, siglen, rsakeylen; | |
5419 | void *hkey; /* actual host key */ | |
5420 | void *rsakey; /* for RSA kex */ | |
5421 | unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN]; | |
5422 | int n_preferred_kex; | |
5423 | const struct ssh_kexes *preferred_kex[KEX_MAX]; | |
5424 | int n_preferred_ciphers; | |
5425 | const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; | |
5426 | const struct ssh_compress *preferred_comp; | |
5427 | int userauth_succeeded; /* for delayed compression */ | |
5428 | int pending_compression; | |
5429 | int got_session_id, activated_authconn; | |
5430 | struct Packet *pktout; | |
5431 | int dlgret; | |
5432 | int guessok; | |
5433 | int ignorepkt; | |
5434 | }; | |
5435 | crState(do_ssh2_transport_state); | |
5436 | ||
5437 | crBegin(ssh->do_ssh2_transport_crstate); | |
5438 | ||
5439 | s->cscipher_tobe = s->sccipher_tobe = NULL; | |
5440 | s->csmac_tobe = s->scmac_tobe = NULL; | |
5441 | s->cscomp_tobe = s->sccomp_tobe = NULL; | |
5442 | ||
5443 | s->got_session_id = s->activated_authconn = FALSE; | |
5444 | s->userauth_succeeded = FALSE; | |
5445 | s->pending_compression = FALSE; | |
5446 | ||
5447 | /* | |
5448 | * Be prepared to work around the buggy MAC problem. | |
5449 | */ | |
5450 | if (ssh->remote_bugs & BUG_SSH2_HMAC) | |
5451 | s->maclist = buggymacs, s->nmacs = lenof(buggymacs); | |
5452 | else | |
5453 | s->maclist = macs, s->nmacs = lenof(macs); | |
5454 | ||
5455 | begin_key_exchange: | |
5456 | ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; | |
5457 | { | |
5458 | int i, j, commalist_started; | |
5459 | ||
5460 | /* | |
5461 | * Set up the preferred key exchange. (NULL => warn below here) | |
5462 | */ | |
5463 | s->n_preferred_kex = 0; | |
5464 | for (i = 0; i < KEX_MAX; i++) { | |
5465 | switch (ssh->cfg.ssh_kexlist[i]) { | |
5466 | case KEX_DHGEX: | |
5467 | s->preferred_kex[s->n_preferred_kex++] = | |
5468 | &ssh_diffiehellman_gex; | |
5469 | break; | |
5470 | case KEX_DHGROUP14: | |
5471 | s->preferred_kex[s->n_preferred_kex++] = | |
5472 | &ssh_diffiehellman_group14; | |
5473 | break; | |
5474 | case KEX_DHGROUP1: | |
5475 | s->preferred_kex[s->n_preferred_kex++] = | |
5476 | &ssh_diffiehellman_group1; | |
5477 | break; | |
5478 | case KEX_RSA: | |
5479 | s->preferred_kex[s->n_preferred_kex++] = | |
5480 | &ssh_rsa_kex; | |
5481 | break; | |
5482 | case KEX_WARN: | |
5483 | /* Flag for later. Don't bother if it's the last in | |
5484 | * the list. */ | |
5485 | if (i < KEX_MAX - 1) { | |
5486 | s->preferred_kex[s->n_preferred_kex++] = NULL; | |
5487 | } | |
5488 | break; | |
5489 | } | |
5490 | } | |
5491 | ||
5492 | /* | |
5493 | * Set up the preferred ciphers. (NULL => warn below here) | |
5494 | */ | |
5495 | s->n_preferred_ciphers = 0; | |
5496 | for (i = 0; i < CIPHER_MAX; i++) { | |
5497 | switch (ssh->cfg.ssh_cipherlist[i]) { | |
5498 | case CIPHER_BLOWFISH: | |
5499 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish; | |
5500 | break; | |
5501 | case CIPHER_DES: | |
5502 | if (ssh->cfg.ssh2_des_cbc) { | |
5503 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des; | |
5504 | } | |
5505 | break; | |
5506 | case CIPHER_3DES: | |
5507 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des; | |
5508 | break; | |
5509 | case CIPHER_AES: | |
5510 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes; | |
5511 | break; | |
5512 | case CIPHER_ARCFOUR: | |
5513 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour; | |
5514 | break; | |
5515 | case CIPHER_WARN: | |
5516 | /* Flag for later. Don't bother if it's the last in | |
5517 | * the list. */ | |
5518 | if (i < CIPHER_MAX - 1) { | |
5519 | s->preferred_ciphers[s->n_preferred_ciphers++] = NULL; | |
5520 | } | |
5521 | break; | |
5522 | } | |
5523 | } | |
5524 | ||
5525 | /* | |
5526 | * Set up preferred compression. | |
5527 | */ | |
5528 | if (ssh->cfg.compression) | |
5529 | s->preferred_comp = &ssh_zlib; | |
5530 | else | |
5531 | s->preferred_comp = &ssh_comp_none; | |
5532 | ||
5533 | /* | |
5534 | * Enable queueing of outgoing auth- or connection-layer | |
5535 | * packets while we are in the middle of a key exchange. | |
5536 | */ | |
5537 | ssh->queueing = TRUE; | |
5538 | ||
5539 | /* | |
5540 | * Flag that KEX is in progress. | |
5541 | */ | |
5542 | ssh->kex_in_progress = TRUE; | |
5543 | ||
5544 | /* | |
5545 | * Construct and send our key exchange packet. | |
5546 | */ | |
5547 | s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); | |
5548 | for (i = 0; i < 16; i++) | |
5549 | ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); | |
5550 | /* List key exchange algorithms. */ | |
5551 | ssh2_pkt_addstring_start(s->pktout); | |
5552 | commalist_started = 0; | |
5553 | for (i = 0; i < s->n_preferred_kex; i++) { | |
5554 | const struct ssh_kexes *k = s->preferred_kex[i]; | |
5555 | if (!k) continue; /* warning flag */ | |
5556 | for (j = 0; j < k->nkexes; j++) { | |
5557 | if (commalist_started) | |
5558 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5559 | ssh2_pkt_addstring_str(s->pktout, k->list[j]->name); | |
5560 | commalist_started = 1; | |
5561 | } | |
5562 | } | |
5563 | /* List server host key algorithms. */ | |
5564 | ssh2_pkt_addstring_start(s->pktout); | |
5565 | for (i = 0; i < lenof(hostkey_algs); i++) { | |
5566 | ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name); | |
5567 | if (i < lenof(hostkey_algs) - 1) | |
5568 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5569 | } | |
5570 | /* List client->server encryption algorithms. */ | |
5571 | ssh2_pkt_addstring_start(s->pktout); | |
5572 | commalist_started = 0; | |
5573 | for (i = 0; i < s->n_preferred_ciphers; i++) { | |
5574 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; | |
5575 | if (!c) continue; /* warning flag */ | |
5576 | for (j = 0; j < c->nciphers; j++) { | |
5577 | if (commalist_started) | |
5578 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5579 | ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); | |
5580 | commalist_started = 1; | |
5581 | } | |
5582 | } | |
5583 | /* List server->client encryption algorithms. */ | |
5584 | ssh2_pkt_addstring_start(s->pktout); | |
5585 | commalist_started = 0; | |
5586 | for (i = 0; i < s->n_preferred_ciphers; i++) { | |
5587 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; | |
5588 | if (!c) continue; /* warning flag */ | |
5589 | for (j = 0; j < c->nciphers; j++) { | |
5590 | if (commalist_started) | |
5591 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5592 | ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); | |
5593 | commalist_started = 1; | |
5594 | } | |
5595 | } | |
5596 | /* List client->server MAC algorithms. */ | |
5597 | ssh2_pkt_addstring_start(s->pktout); | |
5598 | for (i = 0; i < s->nmacs; i++) { | |
5599 | ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); | |
5600 | if (i < s->nmacs - 1) | |
5601 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5602 | } | |
5603 | /* List server->client MAC algorithms. */ | |
5604 | ssh2_pkt_addstring_start(s->pktout); | |
5605 | for (i = 0; i < s->nmacs; i++) { | |
5606 | ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); | |
5607 | if (i < s->nmacs - 1) | |
5608 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5609 | } | |
5610 | /* List client->server compression algorithms, | |
5611 | * then server->client compression algorithms. (We use the | |
5612 | * same set twice.) */ | |
5613 | for (j = 0; j < 2; j++) { | |
5614 | ssh2_pkt_addstring_start(s->pktout); | |
5615 | assert(lenof(compressions) > 1); | |
5616 | /* Prefer non-delayed versions */ | |
5617 | ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name); | |
5618 | /* We don't even list delayed versions of algorithms until | |
5619 | * they're allowed to be used, to avoid a race. See the end of | |
5620 | * this function. */ | |
5621 | if (s->userauth_succeeded && s->preferred_comp->delayed_name) { | |
5622 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5623 | ssh2_pkt_addstring_str(s->pktout, | |
5624 | s->preferred_comp->delayed_name); | |
5625 | } | |
5626 | for (i = 0; i < lenof(compressions); i++) { | |
5627 | const struct ssh_compress *c = compressions[i]; | |
5628 | if (c != s->preferred_comp) { | |
5629 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5630 | ssh2_pkt_addstring_str(s->pktout, c->name); | |
5631 | if (s->userauth_succeeded && c->delayed_name) { | |
5632 | ssh2_pkt_addstring_str(s->pktout, ","); | |
5633 | ssh2_pkt_addstring_str(s->pktout, c->delayed_name); | |
5634 | } | |
5635 | } | |
5636 | } | |
5637 | } | |
5638 | /* List client->server languages. Empty list. */ | |
5639 | ssh2_pkt_addstring_start(s->pktout); | |
5640 | /* List server->client languages. Empty list. */ | |
5641 | ssh2_pkt_addstring_start(s->pktout); | |
5642 | /* First KEX packet does _not_ follow, because we're not that brave. */ | |
5643 | ssh2_pkt_addbool(s->pktout, FALSE); | |
5644 | /* Reserved. */ | |
5645 | ssh2_pkt_adduint32(s->pktout, 0); | |
5646 | } | |
5647 | ||
5648 | s->our_kexinitlen = s->pktout->length - 5; | |
5649 | s->our_kexinit = snewn(s->our_kexinitlen, unsigned char); | |
5650 | memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen); | |
5651 | ||
5652 | ssh2_pkt_send_noqueue(ssh, s->pktout); | |
5653 | ||
5654 | if (!pktin) | |
5655 | crWaitUntil(pktin); | |
5656 | ||
5657 | /* | |
5658 | * Now examine the other side's KEXINIT to see what we're up | |
5659 | * to. | |
5660 | */ | |
5661 | { | |
5662 | char *str, *preferred; | |
5663 | int i, j, len; | |
5664 | ||
5665 | if (pktin->type != SSH2_MSG_KEXINIT) { | |
5666 | bombout(("expected key exchange packet from server")); | |
5667 | crStop(0); | |
5668 | } | |
5669 | ssh->kex = NULL; | |
5670 | ssh->hostkey = NULL; | |
5671 | s->cscipher_tobe = NULL; | |
5672 | s->sccipher_tobe = NULL; | |
5673 | s->csmac_tobe = NULL; | |
5674 | s->scmac_tobe = NULL; | |
5675 | s->cscomp_tobe = NULL; | |
5676 | s->sccomp_tobe = NULL; | |
5677 | s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; | |
5678 | ||
5679 | pktin->savedpos += 16; /* skip garbage cookie */ | |
5680 | ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */ | |
5681 | ||
5682 | preferred = NULL; | |
5683 | for (i = 0; i < s->n_preferred_kex; i++) { | |
5684 | const struct ssh_kexes *k = s->preferred_kex[i]; | |
5685 | if (!k) { | |
5686 | s->warn_kex = TRUE; | |
5687 | } else { | |
5688 | for (j = 0; j < k->nkexes; j++) { | |
5689 | if (!preferred) preferred = k->list[j]->name; | |
5690 | if (in_commasep_string(k->list[j]->name, str, len)) { | |
5691 | ssh->kex = k->list[j]; | |
5692 | break; | |
5693 | } | |
5694 | } | |
5695 | } | |
5696 | if (ssh->kex) | |
5697 | break; | |
5698 | } | |
5699 | if (!ssh->kex) { | |
5700 | bombout(("Couldn't agree a key exchange algorithm (available: %s)", | |
5701 | str ? str : "(null)")); | |
5702 | crStop(0); | |
5703 | } | |
5704 | /* | |
5705 | * Note that the server's guess is considered wrong if it doesn't match | |
5706 | * the first algorithm in our list, even if it's still the algorithm | |
5707 | * we end up using. | |
5708 | */ | |
5709 | s->guessok = first_in_commasep_string(preferred, str, len); | |
5710 | ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */ | |
5711 | for (i = 0; i < lenof(hostkey_algs); i++) { | |
5712 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { | |
5713 | ssh->hostkey = hostkey_algs[i]; | |
5714 | break; | |
5715 | } | |
5716 | } | |
5717 | s->guessok = s->guessok && | |
5718 | first_in_commasep_string(hostkey_algs[0]->name, str, len); | |
5719 | ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ | |
5720 | for (i = 0; i < s->n_preferred_ciphers; i++) { | |
5721 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; | |
5722 | if (!c) { | |
5723 | s->warn_cscipher = TRUE; | |
5724 | } else { | |
5725 | for (j = 0; j < c->nciphers; j++) { | |
5726 | if (in_commasep_string(c->list[j]->name, str, len)) { | |
5727 | s->cscipher_tobe = c->list[j]; | |
5728 | break; | |
5729 | } | |
5730 | } | |
5731 | } | |
5732 | if (s->cscipher_tobe) | |
5733 | break; | |
5734 | } | |
5735 | if (!s->cscipher_tobe) { | |
5736 | bombout(("Couldn't agree a client-to-server cipher (available: %s)", | |
5737 | str ? str : "(null)")); | |
5738 | crStop(0); | |
5739 | } | |
5740 | ||
5741 | ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ | |
5742 | for (i = 0; i < s->n_preferred_ciphers; i++) { | |
5743 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; | |
5744 | if (!c) { | |
5745 | s->warn_sccipher = TRUE; | |
5746 | } else { | |
5747 | for (j = 0; j < c->nciphers; j++) { | |
5748 | if (in_commasep_string(c->list[j]->name, str, len)) { | |
5749 | s->sccipher_tobe = c->list[j]; | |
5750 | break; | |
5751 | } | |
5752 | } | |
5753 | } | |
5754 | if (s->sccipher_tobe) | |
5755 | break; | |
5756 | } | |
5757 | if (!s->sccipher_tobe) { | |
5758 | bombout(("Couldn't agree a server-to-client cipher (available: %s)", | |
5759 | str ? str : "(null)")); | |
5760 | crStop(0); | |
5761 | } | |
5762 | ||
5763 | ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */ | |
5764 | for (i = 0; i < s->nmacs; i++) { | |
5765 | if (in_commasep_string(s->maclist[i]->name, str, len)) { | |
5766 | s->csmac_tobe = s->maclist[i]; | |
5767 | break; | |
5768 | } | |
5769 | } | |
5770 | ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */ | |
5771 | for (i = 0; i < s->nmacs; i++) { | |
5772 | if (in_commasep_string(s->maclist[i]->name, str, len)) { | |
5773 | s->scmac_tobe = s->maclist[i]; | |
5774 | break; | |
5775 | } | |
5776 | } | |
5777 | ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */ | |
5778 | for (i = 0; i < lenof(compressions) + 1; i++) { | |
5779 | const struct ssh_compress *c = | |
5780 | i == 0 ? s->preferred_comp : compressions[i - 1]; | |
5781 | if (in_commasep_string(c->name, str, len)) { | |
5782 | s->cscomp_tobe = c; | |
5783 | break; | |
5784 | } else if (in_commasep_string(c->delayed_name, str, len)) { | |
5785 | if (s->userauth_succeeded) { | |
5786 | s->cscomp_tobe = c; | |
5787 | break; | |
5788 | } else { | |
5789 | s->pending_compression = TRUE; /* try this later */ | |
5790 | } | |
5791 | } | |
5792 | } | |
5793 | ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */ | |
5794 | for (i = 0; i < lenof(compressions) + 1; i++) { | |
5795 | const struct ssh_compress *c = | |
5796 | i == 0 ? s->preferred_comp : compressions[i - 1]; | |
5797 | if (in_commasep_string(c->name, str, len)) { | |
5798 | s->sccomp_tobe = c; | |
5799 | break; | |
5800 | } else if (in_commasep_string(c->delayed_name, str, len)) { | |
5801 | if (s->userauth_succeeded) { | |
5802 | s->sccomp_tobe = c; | |
5803 | break; | |
5804 | } else { | |
5805 | s->pending_compression = TRUE; /* try this later */ | |
5806 | } | |
5807 | } | |
5808 | } | |
5809 | if (s->pending_compression) { | |
5810 | logevent("Server supports delayed compression; " | |
5811 | "will try this later"); | |
5812 | } | |
5813 | ssh_pkt_getstring(pktin, &str, &len); /* client->server language */ | |
5814 | ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ | |
5815 | s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; | |
5816 | ||
5817 | if (s->warn_kex) { | |
5818 | ssh_set_frozen(ssh, 1); | |
5819 | s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", | |
5820 | ssh->kex->name, | |
5821 | ssh_dialog_callback, ssh); | |
5822 | if (s->dlgret < 0) { | |
5823 | do { | |
5824 | crReturn(0); | |
5825 | if (pktin) { | |
5826 | bombout(("Unexpected data from server while" | |
5827 | " waiting for user response")); | |
5828 | crStop(0); | |
5829 | } | |
5830 | } while (pktin || inlen > 0); | |
5831 | s->dlgret = ssh->user_response; | |
5832 | } | |
5833 | ssh_set_frozen(ssh, 0); | |
5834 | if (s->dlgret == 0) { | |
5835 | ssh_disconnect(ssh, "User aborted at kex warning", NULL, | |
5836 | 0, TRUE); | |
5837 | crStop(0); | |
5838 | } | |
5839 | } | |
5840 | ||
5841 | if (s->warn_cscipher) { | |
5842 | ssh_set_frozen(ssh, 1); | |
5843 | s->dlgret = askalg(ssh->frontend, | |
5844 | "client-to-server cipher", | |
5845 | s->cscipher_tobe->name, | |
5846 | ssh_dialog_callback, ssh); | |
5847 | if (s->dlgret < 0) { | |
5848 | do { | |
5849 | crReturn(0); | |
5850 | if (pktin) { | |
5851 | bombout(("Unexpected data from server while" | |
5852 | " waiting for user response")); | |
5853 | crStop(0); | |
5854 | } | |
5855 | } while (pktin || inlen > 0); | |
5856 | s->dlgret = ssh->user_response; | |
5857 | } | |
5858 | ssh_set_frozen(ssh, 0); | |
5859 | if (s->dlgret == 0) { | |
5860 | ssh_disconnect(ssh, "User aborted at cipher warning", NULL, | |
5861 | 0, TRUE); | |
5862 | crStop(0); | |
5863 | } | |
5864 | } | |
5865 | ||
5866 | if (s->warn_sccipher) { | |
5867 | ssh_set_frozen(ssh, 1); | |
5868 | s->dlgret = askalg(ssh->frontend, | |
5869 | "server-to-client cipher", | |
5870 | s->sccipher_tobe->name, | |
5871 | ssh_dialog_callback, ssh); | |
5872 | if (s->dlgret < 0) { | |
5873 | do { | |
5874 | crReturn(0); | |
5875 | if (pktin) { | |
5876 | bombout(("Unexpected data from server while" | |
5877 | " waiting for user response")); | |
5878 | crStop(0); | |
5879 | } | |
5880 | } while (pktin || inlen > 0); | |
5881 | s->dlgret = ssh->user_response; | |
5882 | } | |
5883 | ssh_set_frozen(ssh, 0); | |
5884 | if (s->dlgret == 0) { | |
5885 | ssh_disconnect(ssh, "User aborted at cipher warning", NULL, | |
5886 | 0, TRUE); | |
5887 | crStop(0); | |
5888 | } | |
5889 | } | |
5890 | ||
5891 | ssh->exhash = ssh->kex->hash->init(); | |
5892 | hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); | |
5893 | hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); | |
5894 | hash_string(ssh->kex->hash, ssh->exhash, | |
5895 | s->our_kexinit, s->our_kexinitlen); | |
5896 | sfree(s->our_kexinit); | |
5897 | if (pktin->length > 5) | |
5898 | hash_string(ssh->kex->hash, ssh->exhash, | |
5899 | pktin->data + 5, pktin->length - 5); | |
5900 | ||
5901 | if (s->ignorepkt) /* first_kex_packet_follows */ | |
5902 | crWaitUntil(pktin); /* Ignore packet */ | |
5903 | } | |
5904 | ||
5905 | if (ssh->kex->main_type == KEXTYPE_DH) { | |
5906 | /* | |
5907 | * Work out the number of bits of key we will need from the | |
5908 | * key exchange. We start with the maximum key length of | |
5909 | * either cipher... | |
5910 | */ | |
5911 | { | |
5912 | int csbits, scbits; | |
5913 | ||
5914 | csbits = s->cscipher_tobe->keylen; | |
5915 | scbits = s->sccipher_tobe->keylen; | |
5916 | s->nbits = (csbits > scbits ? csbits : scbits); | |
5917 | } | |
5918 | /* The keys only have hlen-bit entropy, since they're based on | |
5919 | * a hash. So cap the key size at hlen bits. */ | |
5920 | if (s->nbits > ssh->kex->hash->hlen * 8) | |
5921 | s->nbits = ssh->kex->hash->hlen * 8; | |
5922 | ||
5923 | /* | |
5924 | * If we're doing Diffie-Hellman group exchange, start by | |
5925 | * requesting a group. | |
5926 | */ | |
5927 | if (!ssh->kex->pdata) { | |
5928 | logevent("Doing Diffie-Hellman group exchange"); | |
5929 | ssh->pkt_kctx = SSH2_PKTCTX_DHGEX; | |
5930 | /* | |
5931 | * Work out how big a DH group we will need to allow that | |
5932 | * much data. | |
5933 | */ | |
5934 | s->pbits = 512 << ((s->nbits - 1) / 64); | |
5935 | s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); | |
5936 | ssh2_pkt_adduint32(s->pktout, s->pbits); | |
5937 | ssh2_pkt_send_noqueue(ssh, s->pktout); | |
5938 | ||
5939 | crWaitUntil(pktin); | |
5940 | if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) { | |
5941 | bombout(("expected key exchange group packet from server")); | |
5942 | crStop(0); | |
5943 | } | |
5944 | s->p = ssh2_pkt_getmp(pktin); | |
5945 | s->g = ssh2_pkt_getmp(pktin); | |
5946 | if (!s->p || !s->g) { | |
5947 | bombout(("unable to read mp-ints from incoming group packet")); | |
5948 | crStop(0); | |
5949 | } | |
5950 | ssh->kex_ctx = dh_setup_gex(s->p, s->g); | |
5951 | s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; | |
5952 | s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; | |
5953 | } else { | |
5954 | ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP; | |
5955 | ssh->kex_ctx = dh_setup_group(ssh->kex); | |
5956 | s->kex_init_value = SSH2_MSG_KEXDH_INIT; | |
5957 | s->kex_reply_value = SSH2_MSG_KEXDH_REPLY; | |
5958 | logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"", | |
5959 | ssh->kex->groupname); | |
5960 | } | |
5961 | ||
5962 | logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s", | |
5963 | ssh->kex->hash->text_name); | |
5964 | /* | |
5965 | * Now generate and send e for Diffie-Hellman. | |
5966 | */ | |
5967 | set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */ | |
5968 | s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); | |
5969 | s->pktout = ssh2_pkt_init(s->kex_init_value); | |
5970 | ssh2_pkt_addmp(s->pktout, s->e); | |
5971 | ssh2_pkt_send_noqueue(ssh, s->pktout); | |
5972 | ||
5973 | set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */ | |
5974 | crWaitUntil(pktin); | |
5975 | if (pktin->type != s->kex_reply_value) { | |
5976 | bombout(("expected key exchange reply packet from server")); | |
5977 | crStop(0); | |
5978 | } | |
5979 | set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ | |
5980 | ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); | |
5981 | s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); | |
5982 | s->f = ssh2_pkt_getmp(pktin); | |
5983 | if (!s->f) { | |
5984 | bombout(("unable to parse key exchange reply packet")); | |
5985 | crStop(0); | |
5986 | } | |
5987 | ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); | |
5988 | ||
5989 | s->K = dh_find_K(ssh->kex_ctx, s->f); | |
5990 | ||
5991 | /* We assume everything from now on will be quick, and it might | |
5992 | * involve user interaction. */ | |
5993 | set_busy_status(ssh->frontend, BUSY_NOT); | |
5994 | ||
5995 | hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); | |
5996 | if (!ssh->kex->pdata) { | |
5997 | hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits); | |
5998 | hash_mpint(ssh->kex->hash, ssh->exhash, s->p); | |
5999 | hash_mpint(ssh->kex->hash, ssh->exhash, s->g); | |
6000 | } | |
6001 | hash_mpint(ssh->kex->hash, ssh->exhash, s->e); | |
6002 | hash_mpint(ssh->kex->hash, ssh->exhash, s->f); | |
6003 | ||
6004 | dh_cleanup(ssh->kex_ctx); | |
6005 | freebn(s->f); | |
6006 | if (!ssh->kex->pdata) { | |
6007 | freebn(s->g); | |
6008 | freebn(s->p); | |
6009 | } | |
6010 | } else { | |
6011 | logeventf(ssh, "Doing RSA key exchange with hash %s", | |
6012 | ssh->kex->hash->text_name); | |
6013 | ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX; | |
6014 | /* | |
6015 | * RSA key exchange. First expect a KEXRSA_PUBKEY packet | |
6016 | * from the server. | |
6017 | */ | |
6018 | crWaitUntil(pktin); | |
6019 | if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) { | |
6020 | bombout(("expected RSA public key packet from server")); | |
6021 | crStop(0); | |
6022 | } | |
6023 | ||
6024 | ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); | |
6025 | hash_string(ssh->kex->hash, ssh->exhash, | |
6026 | s->hostkeydata, s->hostkeylen); | |
6027 | s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); | |
6028 | ||
6029 | { | |
6030 | char *keydata; | |
6031 | ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen); | |
6032 | s->rsakeydata = snewn(s->rsakeylen, char); | |
6033 | memcpy(s->rsakeydata, keydata, s->rsakeylen); | |
6034 | } | |
6035 | ||
6036 | s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen); | |
6037 | if (!s->rsakey) { | |
6038 | sfree(s->rsakeydata); | |
6039 | bombout(("unable to parse RSA public key from server")); | |
6040 | crStop(0); | |
6041 | } | |
6042 | ||
6043 | hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen); | |
6044 | ||
6045 | /* | |
6046 | * Next, set up a shared secret K, of precisely KLEN - | |
6047 | * 2*HLEN - 49 bits, where KLEN is the bit length of the | |
6048 | * RSA key modulus and HLEN is the bit length of the hash | |
6049 | * we're using. | |
6050 | */ | |
6051 | { | |
6052 | int klen = ssh_rsakex_klen(s->rsakey); | |
6053 | int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49); | |
6054 | int i, byte = 0; | |
6055 | unsigned char *kstr1, *kstr2, *outstr; | |
6056 | int kstr1len, kstr2len, outstrlen; | |
6057 | ||
6058 | s->K = bn_power_2(nbits - 1); | |
6059 | ||
6060 | for (i = 0; i < nbits; i++) { | |
6061 | if ((i & 7) == 0) { | |
6062 | byte = random_byte(); | |
6063 | } | |
6064 | bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1); | |
6065 | } | |
6066 | ||
6067 | /* | |
6068 | * Encode this as an mpint. | |
6069 | */ | |
6070 | kstr1 = ssh2_mpint_fmt(s->K, &kstr1len); | |
6071 | kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char); | |
6072 | PUT_32BIT(kstr2, kstr1len); | |
6073 | memcpy(kstr2 + 4, kstr1, kstr1len); | |
6074 | ||
6075 | /* | |
6076 | * Encrypt it with the given RSA key. | |
6077 | */ | |
6078 | outstrlen = (klen + 7) / 8; | |
6079 | outstr = snewn(outstrlen, unsigned char); | |
6080 | ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len, | |
6081 | outstr, outstrlen, s->rsakey); | |
6082 | ||
6083 | /* | |
6084 | * And send it off in a return packet. | |
6085 | */ | |
6086 | s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET); | |
6087 | ssh2_pkt_addstring_start(s->pktout); | |
6088 | ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen); | |
6089 | ssh2_pkt_send_noqueue(ssh, s->pktout); | |
6090 | ||
6091 | hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen); | |
6092 | ||
6093 | sfree(kstr2); | |
6094 | sfree(kstr1); | |
6095 | sfree(outstr); | |
6096 | } | |
6097 | ||
6098 | ssh_rsakex_freekey(s->rsakey); | |
6099 | ||
6100 | crWaitUntil(pktin); | |
6101 | if (pktin->type != SSH2_MSG_KEXRSA_DONE) { | |
6102 | sfree(s->rsakeydata); | |
6103 | bombout(("expected signature packet from server")); | |
6104 | crStop(0); | |
6105 | } | |
6106 | ||
6107 | ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); | |
6108 | ||
6109 | sfree(s->rsakeydata); | |
6110 | } | |
6111 | ||
6112 | hash_mpint(ssh->kex->hash, ssh->exhash, s->K); | |
6113 | assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash)); | |
6114 | ssh->kex->hash->final(ssh->exhash, s->exchange_hash); | |
6115 | ||
6116 | ssh->kex_ctx = NULL; | |
6117 | ||
6118 | #if 0 | |
6119 | debug(("Exchange hash is:\n")); | |
6120 | dmemdump(s->exchange_hash, ssh->kex->hash->hlen); | |
6121 | #endif | |
6122 | ||
6123 | if (!s->hkey || | |
6124 | !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, | |
6125 | (char *)s->exchange_hash, | |
6126 | ssh->kex->hash->hlen)) { | |
6127 | bombout(("Server's host key did not match the signature supplied")); | |
6128 | crStop(0); | |
6129 | } | |
6130 | ||
6131 | /* | |
6132 | * Authenticate remote host: verify host key. (We've already | |
6133 | * checked the signature of the exchange hash.) | |
6134 | */ | |
6135 | s->keystr = ssh->hostkey->fmtkey(s->hkey); | |
6136 | s->fingerprint = ssh->hostkey->fingerprint(s->hkey); | |
6137 | ssh_set_frozen(ssh, 1); | |
6138 | s->dlgret = verify_ssh_host_key(ssh->frontend, | |
6139 | ssh->savedhost, ssh->savedport, | |
6140 | ssh->hostkey->keytype, s->keystr, | |
6141 | s->fingerprint, | |
6142 | ssh_dialog_callback, ssh); | |
6143 | if (s->dlgret < 0) { | |
6144 | do { | |
6145 | crReturn(0); | |
6146 | if (pktin) { | |
6147 | bombout(("Unexpected data from server while waiting" | |
6148 | " for user host key response")); | |
6149 | crStop(0); | |
6150 | } | |
6151 | } while (pktin || inlen > 0); | |
6152 | s->dlgret = ssh->user_response; | |
6153 | } | |
6154 | ssh_set_frozen(ssh, 0); | |
6155 | if (s->dlgret == 0) { | |
6156 | ssh_disconnect(ssh, "User aborted at host key verification", NULL, | |
6157 | 0, TRUE); | |
6158 | crStop(0); | |
6159 | } | |
6160 | if (!s->got_session_id) { /* don't bother logging this in rekeys */ | |
6161 | logevent("Host key fingerprint is:"); | |
6162 | logevent(s->fingerprint); | |
6163 | } | |
6164 | sfree(s->fingerprint); | |
6165 | sfree(s->keystr); | |
6166 | ssh->hostkey->freekey(s->hkey); | |
6167 | ||
6168 | /* | |
6169 | * The exchange hash from the very first key exchange is also | |
6170 | * the session id, used in session key construction and | |
6171 | * authentication. | |
6172 | */ | |
6173 | if (!s->got_session_id) { | |
6174 | assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id)); | |
6175 | memcpy(ssh->v2_session_id, s->exchange_hash, | |
6176 | sizeof(s->exchange_hash)); | |
6177 | ssh->v2_session_id_len = ssh->kex->hash->hlen; | |
6178 | assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id)); | |
6179 | s->got_session_id = TRUE; | |
6180 | } | |
6181 | ||
6182 | /* | |
6183 | * Send SSH2_MSG_NEWKEYS. | |
6184 | */ | |
6185 | s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS); | |
6186 | ssh2_pkt_send_noqueue(ssh, s->pktout); | |
6187 | ssh->outgoing_data_size = 0; /* start counting from here */ | |
6188 | ||
6189 | /* | |
6190 | * We've sent client NEWKEYS, so create and initialise | |
6191 | * client-to-server session keys. | |
6192 | */ | |
6193 | if (ssh->cs_cipher_ctx) | |
6194 | ssh->cscipher->free_context(ssh->cs_cipher_ctx); | |
6195 | ssh->cscipher = s->cscipher_tobe; | |
6196 | ssh->cs_cipher_ctx = ssh->cscipher->make_context(); | |
6197 | ||
6198 | if (ssh->cs_mac_ctx) | |
6199 | ssh->csmac->free_context(ssh->cs_mac_ctx); | |
6200 | ssh->csmac = s->csmac_tobe; | |
6201 | ssh->cs_mac_ctx = ssh->csmac->make_context(); | |
6202 | ||
6203 | if (ssh->cs_comp_ctx) | |
6204 | ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); | |
6205 | ssh->cscomp = s->cscomp_tobe; | |
6206 | ssh->cs_comp_ctx = ssh->cscomp->compress_init(); | |
6207 | ||
6208 | /* | |
6209 | * Set IVs on client-to-server keys. Here we use the exchange | |
6210 | * hash from the _first_ key exchange. | |
6211 | */ | |
6212 | { | |
6213 | unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; | |
6214 | assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6215 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); | |
6216 | assert((ssh->cscipher->keylen+7) / 8 <= | |
6217 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6218 | ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); | |
6219 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); | |
6220 | assert(ssh->cscipher->blksize <= | |
6221 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6222 | ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); | |
6223 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); | |
6224 | assert(ssh->csmac->len <= | |
6225 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6226 | ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); | |
6227 | memset(keyspace, 0, sizeof(keyspace)); | |
6228 | } | |
6229 | ||
6230 | logeventf(ssh, "Initialised %.200s client->server encryption", | |
6231 | ssh->cscipher->text_name); | |
6232 | logeventf(ssh, "Initialised %.200s client->server MAC algorithm", | |
6233 | ssh->csmac->text_name); | |
6234 | if (ssh->cscomp->text_name) | |
6235 | logeventf(ssh, "Initialised %s compression", | |
6236 | ssh->cscomp->text_name); | |
6237 | ||
6238 | /* | |
6239 | * Now our end of the key exchange is complete, we can send all | |
6240 | * our queued higher-layer packets. | |
6241 | */ | |
6242 | ssh->queueing = FALSE; | |
6243 | ssh2_pkt_queuesend(ssh); | |
6244 | ||
6245 | /* | |
6246 | * Expect SSH2_MSG_NEWKEYS from server. | |
6247 | */ | |
6248 | crWaitUntil(pktin); | |
6249 | if (pktin->type != SSH2_MSG_NEWKEYS) { | |
6250 | bombout(("expected new-keys packet from server")); | |
6251 | crStop(0); | |
6252 | } | |
6253 | ssh->incoming_data_size = 0; /* start counting from here */ | |
6254 | ||
6255 | /* | |
6256 | * We've seen server NEWKEYS, so create and initialise | |
6257 | * server-to-client session keys. | |
6258 | */ | |
6259 | if (ssh->sc_cipher_ctx) | |
6260 | ssh->sccipher->free_context(ssh->sc_cipher_ctx); | |
6261 | ssh->sccipher = s->sccipher_tobe; | |
6262 | ssh->sc_cipher_ctx = ssh->sccipher->make_context(); | |
6263 | ||
6264 | if (ssh->sc_mac_ctx) | |
6265 | ssh->scmac->free_context(ssh->sc_mac_ctx); | |
6266 | ssh->scmac = s->scmac_tobe; | |
6267 | ssh->sc_mac_ctx = ssh->scmac->make_context(); | |
6268 | ||
6269 | if (ssh->sc_comp_ctx) | |
6270 | ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); | |
6271 | ssh->sccomp = s->sccomp_tobe; | |
6272 | ssh->sc_comp_ctx = ssh->sccomp->decompress_init(); | |
6273 | ||
6274 | /* | |
6275 | * Set IVs on server-to-client keys. Here we use the exchange | |
6276 | * hash from the _first_ key exchange. | |
6277 | */ | |
6278 | { | |
6279 | unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; | |
6280 | assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6281 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace); | |
6282 | assert((ssh->sccipher->keylen+7) / 8 <= | |
6283 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6284 | ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); | |
6285 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace); | |
6286 | assert(ssh->sccipher->blksize <= | |
6287 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6288 | ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); | |
6289 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); | |
6290 | assert(ssh->scmac->len <= | |
6291 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); | |
6292 | ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); | |
6293 | memset(keyspace, 0, sizeof(keyspace)); | |
6294 | } | |
6295 | logeventf(ssh, "Initialised %.200s server->client encryption", | |
6296 | ssh->sccipher->text_name); | |
6297 | logeventf(ssh, "Initialised %.200s server->client MAC algorithm", | |
6298 | ssh->scmac->text_name); | |
6299 | if (ssh->sccomp->text_name) | |
6300 | logeventf(ssh, "Initialised %s decompression", | |
6301 | ssh->sccomp->text_name); | |
6302 | ||
6303 | /* | |
6304 | * Free shared secret. | |
6305 | */ | |
6306 | freebn(s->K); | |
6307 | ||
6308 | /* | |
6309 | * Key exchange is over. Loop straight back round if we have a | |
6310 | * deferred rekey reason. | |
6311 | */ | |
6312 | if (ssh->deferred_rekey_reason) { | |
6313 | logevent(ssh->deferred_rekey_reason); | |
6314 | pktin = NULL; | |
6315 | ssh->deferred_rekey_reason = NULL; | |
6316 | goto begin_key_exchange; | |
6317 | } | |
6318 | ||
6319 | /* | |
6320 | * Otherwise, schedule a timer for our next rekey. | |
6321 | */ | |
6322 | ssh->kex_in_progress = FALSE; | |
6323 | ssh->last_rekey = GETTICKCOUNT(); | |
6324 | if (ssh->cfg.ssh_rekey_time != 0) | |
6325 | ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC, | |
6326 | ssh2_timer, ssh); | |
6327 | ||
6328 | /* | |
6329 | * If this is the first key exchange phase, we must pass the | |
6330 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it | |
6331 | * wants to see it but because it will need time to initialise | |
6332 | * itself before it sees an actual packet. In subsequent key | |
6333 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because | |
6334 | * it would only confuse the layer above. | |
6335 | */ | |
6336 | if (s->activated_authconn) { | |
6337 | crReturn(0); | |
6338 | } | |
6339 | s->activated_authconn = TRUE; | |
6340 | ||
6341 | /* | |
6342 | * Now we're encrypting. Begin returning 1 to the protocol main | |
6343 | * function so that other things can run on top of the | |
6344 | * transport. If we ever see a KEXINIT, we must go back to the | |
6345 | * start. | |
6346 | * | |
6347 | * We _also_ go back to the start if we see pktin==NULL and | |
6348 | * inlen negative, because this is a special signal meaning | |
6349 | * `initiate client-driven rekey', and `in' contains a message | |
6350 | * giving the reason for the rekey. | |
6351 | * | |
6352 | * inlen==-1 means always initiate a rekey; | |
6353 | * inlen==-2 means that userauth has completed successfully and | |
6354 | * we should consider rekeying (for delayed compression). | |
6355 | */ | |
6356 | while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) || | |
6357 | (!pktin && inlen < 0))) { | |
6358 | wait_for_rekey: | |
6359 | crReturn(1); | |
6360 | } | |
6361 | if (pktin) { | |
6362 | logevent("Server initiated key re-exchange"); | |
6363 | } else { | |
6364 | if (inlen == -2) { | |
6365 | /* | |
6366 | * authconn has seen a USERAUTH_SUCCEEDED. Time to enable | |
6367 | * delayed compression, if it's available. | |
6368 | * | |
6369 | * draft-miller-secsh-compression-delayed-00 says that you | |
6370 | * negotiate delayed compression in the first key exchange, and | |
6371 | * both sides start compressing when the server has sent | |
6372 | * USERAUTH_SUCCESS. This has a race condition -- the server | |
6373 | * can't know when the client has seen it, and thus which incoming | |
6374 | * packets it should treat as compressed. | |
6375 | * | |
6376 | * Instead, we do the initial key exchange without offering the | |
6377 | * delayed methods, but note if the server offers them; when we | |
6378 | * get here, if a delayed method was available that was higher | |
6379 | * on our list than what we got, we initiate a rekey in which we | |
6380 | * _do_ list the delayed methods (and hopefully get it as a | |
6381 | * result). Subsequent rekeys will do the same. | |
6382 | */ | |
6383 | assert(!s->userauth_succeeded); /* should only happen once */ | |
6384 | s->userauth_succeeded = TRUE; | |
6385 | if (!s->pending_compression) | |
6386 | /* Can't see any point rekeying. */ | |
6387 | goto wait_for_rekey; /* this is utterly horrid */ | |
6388 | /* else fall through to rekey... */ | |
6389 | s->pending_compression = FALSE; | |
6390 | } | |
6391 | /* | |
6392 | * Now we've decided to rekey. | |
6393 | * | |
6394 | * Special case: if the server bug is set that doesn't | |
6395 | * allow rekeying, we give a different log message and | |
6396 | * continue waiting. (If such a server _initiates_ a rekey, | |
6397 | * we process it anyway!) | |
6398 | */ | |
6399 | if ((ssh->remote_bugs & BUG_SSH2_REKEY)) { | |
6400 | logeventf(ssh, "Server bug prevents key re-exchange (%s)", | |
6401 | (char *)in); | |
6402 | /* Reset the counters, so that at least this message doesn't | |
6403 | * hit the event log _too_ often. */ | |
6404 | ssh->outgoing_data_size = 0; | |
6405 | ssh->incoming_data_size = 0; | |
6406 | if (ssh->cfg.ssh_rekey_time != 0) { | |
6407 | ssh->next_rekey = | |
6408 | schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC, | |
6409 | ssh2_timer, ssh); | |
6410 | } | |
6411 | goto wait_for_rekey; /* this is still utterly horrid */ | |
6412 | } else { | |
6413 | logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in); | |
6414 | } | |
6415 | } | |
6416 | goto begin_key_exchange; | |
6417 | ||
6418 | crFinish(1); | |
6419 | } | |
6420 | ||
6421 | /* | |
6422 | * Add data to an SSH-2 channel output buffer. | |
6423 | */ | |
6424 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, | |
6425 | int len) | |
6426 | { | |
6427 | bufchain_add(&c->v.v2.outbuffer, buf, len); | |
6428 | } | |
6429 | ||
6430 | /* | |
6431 | * Attempt to send data on an SSH-2 channel. | |
6432 | */ | |
6433 | static int ssh2_try_send(struct ssh_channel *c) | |
6434 | { | |
6435 | Ssh ssh = c->ssh; | |
6436 | struct Packet *pktout; | |
6437 | ||
6438 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { | |
6439 | int len; | |
6440 | void *data; | |
6441 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); | |
6442 | if ((unsigned)len > c->v.v2.remwindow) | |
6443 | len = c->v.v2.remwindow; | |
6444 | if ((unsigned)len > c->v.v2.remmaxpkt) | |
6445 | len = c->v.v2.remmaxpkt; | |
6446 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); | |
6447 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
6448 | ssh2_pkt_addstring_start(pktout); | |
6449 | dont_log_data(ssh, pktout, PKTLOG_OMIT); | |
6450 | ssh2_pkt_addstring_data(pktout, data, len); | |
6451 | end_log_omission(ssh, pktout); | |
6452 | ssh2_pkt_send(ssh, pktout); | |
6453 | bufchain_consume(&c->v.v2.outbuffer, len); | |
6454 | c->v.v2.remwindow -= len; | |
6455 | } | |
6456 | ||
6457 | /* | |
6458 | * After having sent as much data as we can, return the amount | |
6459 | * still buffered. | |
6460 | */ | |
6461 | return bufchain_size(&c->v.v2.outbuffer); | |
6462 | } | |
6463 | ||
6464 | static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c) | |
6465 | { | |
6466 | int bufsize; | |
6467 | if (c->closes) | |
6468 | return; /* don't send on closing channels */ | |
6469 | bufsize = ssh2_try_send(c); | |
6470 | if (bufsize == 0) { | |
6471 | switch (c->type) { | |
6472 | case CHAN_MAINSESSION: | |
6473 | /* stdin need not receive an unthrottle | |
6474 | * notification since it will be polled */ | |
6475 | break; | |
6476 | case CHAN_X11: | |
6477 | x11_unthrottle(c->u.x11.s); | |
6478 | break; | |
6479 | case CHAN_AGENT: | |
6480 | /* agent sockets are request/response and need no | |
6481 | * buffer management */ | |
6482 | break; | |
6483 | case CHAN_SOCKDATA: | |
6484 | pfd_unthrottle(c->u.pfd.s); | |
6485 | break; | |
6486 | } | |
6487 | } | |
6488 | ||
6489 | /* | |
6490 | * If we've emptied the channel's output buffer and there's a | |
6491 | * pending close event, start the channel-closing procedure. | |
6492 | */ | |
6493 | if (c->pending_close && bufchain_size(&c->v.v2.outbuffer) == 0) { | |
6494 | struct Packet *pktout; | |
6495 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); | |
6496 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
6497 | ssh2_pkt_send(ssh, pktout); | |
6498 | c->closes = 1; | |
6499 | c->pending_close = FALSE; | |
6500 | } | |
6501 | } | |
6502 | ||
6503 | /* | |
6504 | * Set up most of a new ssh_channel for SSH-2. | |
6505 | */ | |
6506 | static void ssh2_channel_init(struct ssh_channel *c) | |
6507 | { | |
6508 | Ssh ssh = c->ssh; | |
6509 | c->localid = alloc_channel_id(ssh); | |
6510 | c->closes = 0; | |
6511 | c->pending_close = FALSE; | |
6512 | c->throttling_conn = FALSE; | |
6513 | c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = | |
6514 | ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; | |
6515 | c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL; | |
6516 | c->v.v2.throttle_state = UNTHROTTLED; | |
6517 | bufchain_init(&c->v.v2.outbuffer); | |
6518 | } | |
6519 | ||
6520 | /* | |
6521 | * Potentially enlarge the window on an SSH-2 channel. | |
6522 | */ | |
6523 | static void ssh2_set_window(struct ssh_channel *c, int newwin) | |
6524 | { | |
6525 | Ssh ssh = c->ssh; | |
6526 | ||
6527 | /* | |
6528 | * Never send WINDOW_ADJUST for a channel that the remote side | |
6529 | * already thinks it's closed; there's no point, since it won't | |
6530 | * be sending any more data anyway. | |
6531 | */ | |
6532 | if (c->closes != 0) | |
6533 | return; | |
6534 | ||
6535 | /* | |
6536 | * If the remote end has a habit of ignoring maxpkt, limit the | |
6537 | * window so that it has no choice (assuming it doesn't ignore the | |
6538 | * window as well). | |
6539 | */ | |
6540 | if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT) | |
6541 | newwin = OUR_V2_MAXPKT; | |
6542 | ||
6543 | ||
6544 | /* | |
6545 | * Only send a WINDOW_ADJUST if there's significantly more window | |
6546 | * available than the other end thinks there is. This saves us | |
6547 | * sending a WINDOW_ADJUST for every character in a shell session. | |
6548 | * | |
6549 | * "Significant" is arbitrarily defined as half the window size. | |
6550 | */ | |
6551 | if (newwin / 2 >= c->v.v2.locwindow) { | |
6552 | struct Packet *pktout; | |
6553 | struct winadj *wa; | |
6554 | ||
6555 | /* | |
6556 | * In order to keep track of how much window the client | |
6557 | * actually has available, we'd like it to acknowledge each | |
6558 | * WINDOW_ADJUST. We can't do that directly, so we accompany | |
6559 | * it with a CHANNEL_REQUEST that has to be acknowledged. | |
6560 | * | |
6561 | * This is only necessary if we're opening the window wide. | |
6562 | * If we're not, then throughput is being constrained by | |
6563 | * something other than the maximum window size anyway. | |
6564 | * | |
6565 | * We also only send this if the main channel has finished its | |
6566 | * initial CHANNEL_REQUESTs and installed the default | |
6567 | * CHANNEL_FAILURE handler, so as not to risk giving it | |
6568 | * unexpected CHANNEL_FAILUREs. | |
6569 | */ | |
6570 | if (newwin == c->v.v2.locmaxwin && | |
6571 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) { | |
6572 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
6573 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
6574 | ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org"); | |
6575 | ssh2_pkt_addbool(pktout, TRUE); | |
6576 | ssh2_pkt_send(ssh, pktout); | |
6577 | ||
6578 | /* | |
6579 | * CHANNEL_FAILURE doesn't come with any indication of | |
6580 | * what message caused it, so we have to keep track of the | |
6581 | * outstanding CHANNEL_REQUESTs ourselves. | |
6582 | */ | |
6583 | wa = snew(struct winadj); | |
6584 | wa->size = newwin - c->v.v2.locwindow; | |
6585 | wa->next = NULL; | |
6586 | if (!c->v.v2.winadj_head) | |
6587 | c->v.v2.winadj_head = wa; | |
6588 | else | |
6589 | c->v.v2.winadj_tail->next = wa; | |
6590 | c->v.v2.winadj_tail = wa; | |
6591 | if (c->v.v2.throttle_state != UNTHROTTLED) | |
6592 | c->v.v2.throttle_state = UNTHROTTLING; | |
6593 | } else { | |
6594 | /* Pretend the WINDOW_ADJUST was acked immediately. */ | |
6595 | c->v.v2.remlocwin = newwin; | |
6596 | c->v.v2.throttle_state = THROTTLED; | |
6597 | } | |
6598 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
6599 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
6600 | ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow); | |
6601 | ssh2_pkt_send(ssh, pktout); | |
6602 | c->v.v2.locwindow = newwin; | |
6603 | } | |
6604 | } | |
6605 | ||
6606 | /* | |
6607 | * Find the channel associated with a message. If there's no channel, | |
6608 | * or it's not properly open, make a noise about it and return NULL. | |
6609 | */ | |
6610 | static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin) | |
6611 | { | |
6612 | unsigned localid = ssh_pkt_getuint32(pktin); | |
6613 | struct ssh_channel *c; | |
6614 | ||
6615 | c = find234(ssh->channels, &localid, ssh_channelfind); | |
6616 | if (!c || | |
6617 | (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION && | |
6618 | pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) { | |
6619 | char *buf = dupprintf("Received %s for %s channel %u", | |
6620 | ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, | |
6621 | pktin->type), | |
6622 | c ? "half-open" : "nonexistent", localid); | |
6623 | ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); | |
6624 | sfree(buf); | |
6625 | return NULL; | |
6626 | } | |
6627 | return c; | |
6628 | } | |
6629 | ||
6630 | static int ssh2_handle_winadj_response(struct ssh_channel *c) | |
6631 | { | |
6632 | struct winadj *wa = c->v.v2.winadj_head; | |
6633 | if (!wa) | |
6634 | return FALSE; | |
6635 | c->v.v2.winadj_head = wa->next; | |
6636 | c->v.v2.remlocwin += wa->size; | |
6637 | sfree(wa); | |
6638 | /* | |
6639 | * winadj messages are only sent when the window is fully open, so | |
6640 | * if we get an ack of one, we know any pending unthrottle is | |
6641 | * complete. | |
6642 | */ | |
6643 | if (c->v.v2.throttle_state == UNTHROTTLING) | |
6644 | c->v.v2.throttle_state = UNTHROTTLED; | |
6645 | return TRUE; | |
6646 | } | |
6647 | ||
6648 | static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin) | |
6649 | { | |
6650 | /* | |
6651 | * This should never get called. All channel requests are either | |
6652 | * sent with want_reply false, are sent before this handler gets | |
6653 | * installed, or are "winadj@putty" requests, which servers should | |
6654 | * never respond to with success. | |
6655 | * | |
6656 | * However, at least one server ("boks_sshd") is known to return | |
6657 | * SUCCESS for channel requests it's never heard of, such as | |
6658 | * "winadj@putty". Raised with foxt.com as bug 090916-090424, but | |
6659 | * for the sake of a quiet life, we handle it just the same as the | |
6660 | * expected FAILURE. | |
6661 | */ | |
6662 | struct ssh_channel *c; | |
6663 | ||
6664 | c = ssh2_channel_msg(ssh, pktin); | |
6665 | if (!c) | |
6666 | return; | |
6667 | if (!ssh2_handle_winadj_response(c)) | |
6668 | ssh_disconnect(ssh, NULL, | |
6669 | "Received unsolicited SSH_MSG_CHANNEL_SUCCESS", | |
6670 | SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); | |
6671 | } | |
6672 | ||
6673 | static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin) | |
6674 | { | |
6675 | /* | |
6676 | * The only time this should get called is for "winadj@putty" | |
6677 | * messages sent above. All other channel requests are either | |
6678 | * sent with want_reply false or are sent before this handler gets | |
6679 | * installed. | |
6680 | */ | |
6681 | struct ssh_channel *c; | |
6682 | ||
6683 | c = ssh2_channel_msg(ssh, pktin); | |
6684 | if (!c) | |
6685 | return; | |
6686 | if (!ssh2_handle_winadj_response(c)) | |
6687 | ssh_disconnect(ssh, NULL, | |
6688 | "Received unsolicited SSH_MSG_CHANNEL_FAILURE", | |
6689 | SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); | |
6690 | } | |
6691 | ||
6692 | static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) | |
6693 | { | |
6694 | struct ssh_channel *c; | |
6695 | c = ssh2_channel_msg(ssh, pktin); | |
6696 | if (!c) | |
6697 | return; | |
6698 | if (!c->closes) { | |
6699 | c->v.v2.remwindow += ssh_pkt_getuint32(pktin); | |
6700 | ssh2_try_send_and_unthrottle(ssh, c); | |
6701 | } | |
6702 | } | |
6703 | ||
6704 | static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) | |
6705 | { | |
6706 | char *data; | |
6707 | int length; | |
6708 | struct ssh_channel *c; | |
6709 | c = ssh2_channel_msg(ssh, pktin); | |
6710 | if (!c) | |
6711 | return; | |
6712 | if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && | |
6713 | ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) | |
6714 | return; /* extended but not stderr */ | |
6715 | ssh_pkt_getstring(pktin, &data, &length); | |
6716 | if (data) { | |
6717 | int bufsize = 0; | |
6718 | c->v.v2.locwindow -= length; | |
6719 | c->v.v2.remlocwin -= length; | |
6720 | switch (c->type) { | |
6721 | case CHAN_MAINSESSION: | |
6722 | bufsize = | |
6723 | from_backend(ssh->frontend, pktin->type == | |
6724 | SSH2_MSG_CHANNEL_EXTENDED_DATA, | |
6725 | data, length); | |
6726 | break; | |
6727 | case CHAN_X11: | |
6728 | bufsize = x11_send(c->u.x11.s, data, length); | |
6729 | break; | |
6730 | case CHAN_SOCKDATA: | |
6731 | bufsize = pfd_send(c->u.pfd.s, data, length); | |
6732 | break; | |
6733 | case CHAN_AGENT: | |
6734 | while (length > 0) { | |
6735 | if (c->u.a.lensofar < 4) { | |
6736 | unsigned int l = min(4 - c->u.a.lensofar, | |
6737 | (unsigned)length); | |
6738 | memcpy(c->u.a.msglen + c->u.a.lensofar, | |
6739 | data, l); | |
6740 | data += l; | |
6741 | length -= l; | |
6742 | c->u.a.lensofar += l; | |
6743 | } | |
6744 | if (c->u.a.lensofar == 4) { | |
6745 | c->u.a.totallen = | |
6746 | 4 + GET_32BIT(c->u.a.msglen); | |
6747 | c->u.a.message = snewn(c->u.a.totallen, | |
6748 | unsigned char); | |
6749 | memcpy(c->u.a.message, c->u.a.msglen, 4); | |
6750 | } | |
6751 | if (c->u.a.lensofar >= 4 && length > 0) { | |
6752 | unsigned int l = | |
6753 | min(c->u.a.totallen - c->u.a.lensofar, | |
6754 | (unsigned)length); | |
6755 | memcpy(c->u.a.message + c->u.a.lensofar, | |
6756 | data, l); | |
6757 | data += l; | |
6758 | length -= l; | |
6759 | c->u.a.lensofar += l; | |
6760 | } | |
6761 | if (c->u.a.lensofar == c->u.a.totallen) { | |
6762 | void *reply; | |
6763 | int replylen; | |
6764 | if (agent_query(c->u.a.message, | |
6765 | c->u.a.totallen, | |
6766 | &reply, &replylen, | |
6767 | ssh_agentf_callback, c)) | |
6768 | ssh_agentf_callback(c, reply, replylen); | |
6769 | sfree(c->u.a.message); | |
6770 | c->u.a.lensofar = 0; | |
6771 | } | |
6772 | } | |
6773 | bufsize = 0; | |
6774 | break; | |
6775 | } | |
6776 | /* | |
6777 | * If it looks like the remote end hit the end of its window, | |
6778 | * and we didn't want it to do that, think about using a | |
6779 | * larger window. | |
6780 | */ | |
6781 | if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED && | |
6782 | c->v.v2.locmaxwin < 0x40000000) | |
6783 | c->v.v2.locmaxwin += OUR_V2_WINSIZE; | |
6784 | /* | |
6785 | * If we are not buffering too much data, | |
6786 | * enlarge the window again at the remote side. | |
6787 | * If we are buffering too much, we may still | |
6788 | * need to adjust the window if the server's | |
6789 | * sent excess data. | |
6790 | */ | |
6791 | ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ? | |
6792 | c->v.v2.locmaxwin - bufsize : 0); | |
6793 | /* | |
6794 | * If we're either buffering way too much data, or if we're | |
6795 | * buffering anything at all and we're in "simple" mode, | |
6796 | * throttle the whole channel. | |
6797 | */ | |
6798 | if ((bufsize > c->v.v2.locmaxwin || | |
6799 | (ssh->cfg.ssh_simple && bufsize > 0)) && | |
6800 | !c->throttling_conn) { | |
6801 | c->throttling_conn = 1; | |
6802 | ssh_throttle_conn(ssh, +1); | |
6803 | } | |
6804 | } | |
6805 | } | |
6806 | ||
6807 | static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) | |
6808 | { | |
6809 | struct ssh_channel *c; | |
6810 | ||
6811 | c = ssh2_channel_msg(ssh, pktin); | |
6812 | if (!c) | |
6813 | return; | |
6814 | ||
6815 | if (c->type == CHAN_X11) { | |
6816 | /* | |
6817 | * Remote EOF on an X11 channel means we should | |
6818 | * wrap up and close the channel ourselves. | |
6819 | */ | |
6820 | x11_close(c->u.x11.s); | |
6821 | c->u.x11.s = NULL; | |
6822 | sshfwd_close(c); | |
6823 | } else if (c->type == CHAN_AGENT) { | |
6824 | sshfwd_close(c); | |
6825 | } else if (c->type == CHAN_SOCKDATA) { | |
6826 | pfd_close(c->u.pfd.s); | |
6827 | c->u.pfd.s = NULL; | |
6828 | sshfwd_close(c); | |
6829 | } | |
6830 | } | |
6831 | ||
6832 | static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) | |
6833 | { | |
6834 | struct ssh_channel *c; | |
6835 | struct Packet *pktout; | |
6836 | ||
6837 | c = ssh2_channel_msg(ssh, pktin); | |
6838 | if (!c) | |
6839 | return; | |
6840 | /* Do pre-close processing on the channel. */ | |
6841 | switch (c->type) { | |
6842 | case CHAN_MAINSESSION: | |
6843 | ssh->mainchan = NULL; | |
6844 | update_specials_menu(ssh->frontend); | |
6845 | break; | |
6846 | case CHAN_X11: | |
6847 | if (c->u.x11.s != NULL) | |
6848 | x11_close(c->u.x11.s); | |
6849 | sshfwd_close(c); | |
6850 | break; | |
6851 | case CHAN_AGENT: | |
6852 | sshfwd_close(c); | |
6853 | break; | |
6854 | case CHAN_SOCKDATA: | |
6855 | if (c->u.pfd.s != NULL) | |
6856 | pfd_close(c->u.pfd.s); | |
6857 | sshfwd_close(c); | |
6858 | break; | |
6859 | } | |
6860 | if (c->closes == 0) { | |
6861 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); | |
6862 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
6863 | ssh2_pkt_send(ssh, pktout); | |
6864 | } | |
6865 | del234(ssh->channels, c); | |
6866 | bufchain_clear(&c->v.v2.outbuffer); | |
6867 | sfree(c); | |
6868 | ||
6869 | /* | |
6870 | * See if that was the last channel left open. | |
6871 | * (This is only our termination condition if we're | |
6872 | * not running in -N mode.) | |
6873 | */ | |
6874 | if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) { | |
6875 | /* | |
6876 | * We used to send SSH_MSG_DISCONNECT here, | |
6877 | * because I'd believed that _every_ conforming | |
6878 | * SSH-2 connection had to end with a disconnect | |
6879 | * being sent by at least one side; apparently | |
6880 | * I was wrong and it's perfectly OK to | |
6881 | * unceremoniously slam the connection shut | |
6882 | * when you're done, and indeed OpenSSH feels | |
6883 | * this is more polite than sending a | |
6884 | * DISCONNECT. So now we don't. | |
6885 | */ | |
6886 | ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); | |
6887 | } | |
6888 | } | |
6889 | ||
6890 | static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) | |
6891 | { | |
6892 | struct ssh_channel *c; | |
6893 | struct Packet *pktout; | |
6894 | ||
6895 | c = ssh2_channel_msg(ssh, pktin); | |
6896 | if (!c) | |
6897 | return; | |
6898 | if (c->type != CHAN_SOCKDATA_DORMANT) | |
6899 | return; /* dunno why they're confirming this */ | |
6900 | c->remoteid = ssh_pkt_getuint32(pktin); | |
6901 | c->halfopen = FALSE; | |
6902 | c->type = CHAN_SOCKDATA; | |
6903 | c->v.v2.remwindow = ssh_pkt_getuint32(pktin); | |
6904 | c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); | |
6905 | if (c->u.pfd.s) | |
6906 | pfd_confirm(c->u.pfd.s); | |
6907 | if (c->closes) { | |
6908 | /* | |
6909 | * We have a pending close on this channel, | |
6910 | * which we decided on before the server acked | |
6911 | * the channel open. So now we know the | |
6912 | * remoteid, we can close it again. | |
6913 | */ | |
6914 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); | |
6915 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
6916 | ssh2_pkt_send(ssh, pktout); | |
6917 | } | |
6918 | } | |
6919 | ||
6920 | static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) | |
6921 | { | |
6922 | static const char *const reasons[] = { | |
6923 | "<unknown reason code>", | |
6924 | "Administratively prohibited", | |
6925 | "Connect failed", | |
6926 | "Unknown channel type", | |
6927 | "Resource shortage", | |
6928 | }; | |
6929 | unsigned reason_code; | |
6930 | char *reason_string; | |
6931 | int reason_length; | |
6932 | struct ssh_channel *c; | |
6933 | c = ssh2_channel_msg(ssh, pktin); | |
6934 | if (!c) | |
6935 | return; | |
6936 | if (c->type != CHAN_SOCKDATA_DORMANT) | |
6937 | return; /* dunno why they're failing this */ | |
6938 | ||
6939 | reason_code = ssh_pkt_getuint32(pktin); | |
6940 | if (reason_code >= lenof(reasons)) | |
6941 | reason_code = 0; /* ensure reasons[reason_code] in range */ | |
6942 | ssh_pkt_getstring(pktin, &reason_string, &reason_length); | |
6943 | logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", | |
6944 | reasons[reason_code], reason_length, reason_string); | |
6945 | ||
6946 | pfd_close(c->u.pfd.s); | |
6947 | ||
6948 | del234(ssh->channels, c); | |
6949 | sfree(c); | |
6950 | } | |
6951 | ||
6952 | static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) | |
6953 | { | |
6954 | char *type; | |
6955 | int typelen, want_reply; | |
6956 | int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ | |
6957 | struct ssh_channel *c; | |
6958 | struct Packet *pktout; | |
6959 | ||
6960 | c = ssh2_channel_msg(ssh, pktin); | |
6961 | if (!c) | |
6962 | return; | |
6963 | ssh_pkt_getstring(pktin, &type, &typelen); | |
6964 | want_reply = ssh2_pkt_getbool(pktin); | |
6965 | ||
6966 | /* | |
6967 | * Having got the channel number, we now look at | |
6968 | * the request type string to see if it's something | |
6969 | * we recognise. | |
6970 | */ | |
6971 | if (c == ssh->mainchan) { | |
6972 | /* | |
6973 | * We recognise "exit-status" and "exit-signal" on | |
6974 | * the primary channel. | |
6975 | */ | |
6976 | if (typelen == 11 && | |
6977 | !memcmp(type, "exit-status", 11)) { | |
6978 | ||
6979 | ssh->exitcode = ssh_pkt_getuint32(pktin); | |
6980 | logeventf(ssh, "Server sent command exit status %d", | |
6981 | ssh->exitcode); | |
6982 | reply = SSH2_MSG_CHANNEL_SUCCESS; | |
6983 | ||
6984 | } else if (typelen == 11 && | |
6985 | !memcmp(type, "exit-signal", 11)) { | |
6986 | ||
6987 | int is_plausible = TRUE, is_int = FALSE; | |
6988 | char *fmt_sig = "", *fmt_msg = ""; | |
6989 | char *msg; | |
6990 | int msglen = 0, core = FALSE; | |
6991 | /* ICK: older versions of OpenSSH (e.g. 3.4p1) | |
6992 | * provide an `int' for the signal, despite its | |
6993 | * having been a `string' in the drafts of RFC 4254 since at | |
6994 | * least 2001. (Fixed in session.c 1.147.) Try to | |
6995 | * infer which we can safely parse it as. */ | |
6996 | { | |
6997 | unsigned char *p = pktin->body + | |
6998 | pktin->savedpos; | |
6999 | long len = pktin->length - pktin->savedpos; | |
7000 | unsigned long num = GET_32BIT(p); /* what is it? */ | |
7001 | /* If it's 0, it hardly matters; assume string */ | |
7002 | if (num == 0) { | |
7003 | is_int = FALSE; | |
7004 | } else { | |
7005 | int maybe_int = FALSE, maybe_str = FALSE; | |
7006 | #define CHECK_HYPOTHESIS(offset, result) \ | |
7007 | do { \ | |
7008 | long q = offset; \ | |
7009 | if (q >= 0 && q+4 <= len) { \ | |
7010 | q = q + 4 + GET_32BIT(p+q); \ | |
7011 | if (q >= 0 && q+4 <= len && \ | |
7012 | ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \ | |
7013 | result = TRUE; \ | |
7014 | } \ | |
7015 | } while(0) | |
7016 | CHECK_HYPOTHESIS(4+1, maybe_int); | |
7017 | CHECK_HYPOTHESIS(4+num+1, maybe_str); | |
7018 | #undef CHECK_HYPOTHESIS | |
7019 | if (maybe_int && !maybe_str) | |
7020 | is_int = TRUE; | |
7021 | else if (!maybe_int && maybe_str) | |
7022 | is_int = FALSE; | |
7023 | else | |
7024 | /* Crikey. Either or neither. Panic. */ | |
7025 | is_plausible = FALSE; | |
7026 | } | |
7027 | } | |
7028 | ssh->exitcode = 128; /* means `unknown signal' */ | |
7029 | if (is_plausible) { | |
7030 | if (is_int) { | |
7031 | /* Old non-standard OpenSSH. */ | |
7032 | int signum = ssh_pkt_getuint32(pktin); | |
7033 | fmt_sig = dupprintf(" %d", signum); | |
7034 | ssh->exitcode = 128 + signum; | |
7035 | } else { | |
7036 | /* As per RFC 4254. */ | |
7037 | char *sig; | |
7038 | int siglen; | |
7039 | ssh_pkt_getstring(pktin, &sig, &siglen); | |
7040 | /* Signal name isn't supposed to be blank, but | |
7041 | * let's cope gracefully if it is. */ | |
7042 | if (siglen) { | |
7043 | fmt_sig = dupprintf(" \"%.*s\"", | |
7044 | siglen, sig); | |
7045 | } | |
7046 | ||
7047 | /* | |
7048 | * Really hideous method of translating the | |
7049 | * signal description back into a locally | |
7050 | * meaningful number. | |
7051 | */ | |
7052 | ||
7053 | if (0) | |
7054 | ; | |
7055 | #define TRANSLATE_SIGNAL(s) \ | |
7056 | else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \ | |
7057 | ssh->exitcode = 128 + SIG ## s | |
7058 | #ifdef SIGABRT | |
7059 | TRANSLATE_SIGNAL(ABRT); | |
7060 | #endif | |
7061 | #ifdef SIGALRM | |
7062 | TRANSLATE_SIGNAL(ALRM); | |
7063 | #endif | |
7064 | #ifdef SIGFPE | |
7065 | TRANSLATE_SIGNAL(FPE); | |
7066 | #endif | |
7067 | #ifdef SIGHUP | |
7068 | TRANSLATE_SIGNAL(HUP); | |
7069 | #endif | |
7070 | #ifdef SIGILL | |
7071 | TRANSLATE_SIGNAL(ILL); | |
7072 | #endif | |
7073 | #ifdef SIGINT | |
7074 | TRANSLATE_SIGNAL(INT); | |
7075 | #endif | |
7076 | #ifdef SIGKILL | |
7077 | TRANSLATE_SIGNAL(KILL); | |
7078 | #endif | |
7079 | #ifdef SIGPIPE | |
7080 | TRANSLATE_SIGNAL(PIPE); | |
7081 | #endif | |
7082 | #ifdef SIGQUIT | |
7083 | TRANSLATE_SIGNAL(QUIT); | |
7084 | #endif | |
7085 | #ifdef SIGSEGV | |
7086 | TRANSLATE_SIGNAL(SEGV); | |
7087 | #endif | |
7088 | #ifdef SIGTERM | |
7089 | TRANSLATE_SIGNAL(TERM); | |
7090 | #endif | |
7091 | #ifdef SIGUSR1 | |
7092 | TRANSLATE_SIGNAL(USR1); | |
7093 | #endif | |
7094 | #ifdef SIGUSR2 | |
7095 | TRANSLATE_SIGNAL(USR2); | |
7096 | #endif | |
7097 | #undef TRANSLATE_SIGNAL | |
7098 | else | |
7099 | ssh->exitcode = 128; | |
7100 | } | |
7101 | core = ssh2_pkt_getbool(pktin); | |
7102 | ssh_pkt_getstring(pktin, &msg, &msglen); | |
7103 | if (msglen) { | |
7104 | fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg); | |
7105 | } | |
7106 | /* ignore lang tag */ | |
7107 | } /* else don't attempt to parse */ | |
7108 | logeventf(ssh, "Server exited on signal%s%s%s", | |
7109 | fmt_sig, core ? " (core dumped)" : "", | |
7110 | fmt_msg); | |
7111 | if (*fmt_sig) sfree(fmt_sig); | |
7112 | if (*fmt_msg) sfree(fmt_msg); | |
7113 | reply = SSH2_MSG_CHANNEL_SUCCESS; | |
7114 | ||
7115 | } | |
7116 | } else { | |
7117 | /* | |
7118 | * This is a channel request we don't know | |
7119 | * about, so we now either ignore the request | |
7120 | * or respond with CHANNEL_FAILURE, depending | |
7121 | * on want_reply. | |
7122 | */ | |
7123 | reply = SSH2_MSG_CHANNEL_FAILURE; | |
7124 | } | |
7125 | if (want_reply) { | |
7126 | pktout = ssh2_pkt_init(reply); | |
7127 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
7128 | ssh2_pkt_send(ssh, pktout); | |
7129 | } | |
7130 | } | |
7131 | ||
7132 | static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin) | |
7133 | { | |
7134 | char *type; | |
7135 | int typelen, want_reply; | |
7136 | struct Packet *pktout; | |
7137 | ||
7138 | ssh_pkt_getstring(pktin, &type, &typelen); | |
7139 | want_reply = ssh2_pkt_getbool(pktin); | |
7140 | ||
7141 | /* | |
7142 | * We currently don't support any global requests | |
7143 | * at all, so we either ignore the request or | |
7144 | * respond with REQUEST_FAILURE, depending on | |
7145 | * want_reply. | |
7146 | */ | |
7147 | if (want_reply) { | |
7148 | pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); | |
7149 | ssh2_pkt_send(ssh, pktout); | |
7150 | } | |
7151 | } | |
7152 | ||
7153 | static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) | |
7154 | { | |
7155 | char *type; | |
7156 | int typelen; | |
7157 | char *peeraddr; | |
7158 | int peeraddrlen; | |
7159 | int peerport; | |
7160 | char *error = NULL; | |
7161 | struct ssh_channel *c; | |
7162 | unsigned remid, winsize, pktsize; | |
7163 | struct Packet *pktout; | |
7164 | ||
7165 | ssh_pkt_getstring(pktin, &type, &typelen); | |
7166 | c = snew(struct ssh_channel); | |
7167 | c->ssh = ssh; | |
7168 | ||
7169 | remid = ssh_pkt_getuint32(pktin); | |
7170 | winsize = ssh_pkt_getuint32(pktin); | |
7171 | pktsize = ssh_pkt_getuint32(pktin); | |
7172 | ||
7173 | if (typelen == 3 && !memcmp(type, "x11", 3)) { | |
7174 | char *addrstr; | |
7175 | const char *x11err; | |
7176 | ||
7177 | ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); | |
7178 | addrstr = snewn(peeraddrlen+1, char); | |
7179 | memcpy(addrstr, peeraddr, peeraddrlen); | |
7180 | addrstr[peeraddrlen] = '\0'; | |
7181 | peerport = ssh_pkt_getuint32(pktin); | |
7182 | ||
7183 | logeventf(ssh, "Received X11 connect request from %s:%d", | |
7184 | addrstr, peerport); | |
7185 | ||
7186 | if (!ssh->X11_fwd_enabled) | |
7187 | error = "X11 forwarding is not enabled"; | |
7188 | else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c, | |
7189 | addrstr, peerport, &ssh->cfg)) != NULL) { | |
7190 | logeventf(ssh, "Local X11 connection failed: %s", x11err); | |
7191 | error = "Unable to open an X11 connection"; | |
7192 | } else { | |
7193 | logevent("Opening X11 forward connection succeeded"); | |
7194 | c->type = CHAN_X11; | |
7195 | } | |
7196 | ||
7197 | sfree(addrstr); | |
7198 | } else if (typelen == 15 && | |
7199 | !memcmp(type, "forwarded-tcpip", 15)) { | |
7200 | struct ssh_rportfwd pf, *realpf; | |
7201 | char *dummy; | |
7202 | int dummylen; | |
7203 | ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */ | |
7204 | pf.sport = ssh_pkt_getuint32(pktin); | |
7205 | ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); | |
7206 | peerport = ssh_pkt_getuint32(pktin); | |
7207 | realpf = find234(ssh->rportfwds, &pf, NULL); | |
7208 | logeventf(ssh, "Received remote port %d open request " | |
7209 | "from %s:%d", pf.sport, peeraddr, peerport); | |
7210 | if (realpf == NULL) { | |
7211 | error = "Remote port is not recognised"; | |
7212 | } else { | |
7213 | const char *e = pfd_newconnect(&c->u.pfd.s, | |
7214 | realpf->dhost, | |
7215 | realpf->dport, c, | |
7216 | &ssh->cfg, | |
7217 | realpf->pfrec->addressfamily); | |
7218 | logeventf(ssh, "Attempting to forward remote port to " | |
7219 | "%s:%d", realpf->dhost, realpf->dport); | |
7220 | if (e != NULL) { | |
7221 | logeventf(ssh, "Port open failed: %s", e); | |
7222 | error = "Port open failed"; | |
7223 | } else { | |
7224 | logevent("Forwarded port opened successfully"); | |
7225 | c->type = CHAN_SOCKDATA; | |
7226 | } | |
7227 | } | |
7228 | } else if (typelen == 22 && | |
7229 | !memcmp(type, "auth-agent@openssh.com", 22)) { | |
7230 | if (!ssh->agentfwd_enabled) | |
7231 | error = "Agent forwarding is not enabled"; | |
7232 | else { | |
7233 | c->type = CHAN_AGENT; /* identify channel type */ | |
7234 | c->u.a.lensofar = 0; | |
7235 | } | |
7236 | } else { | |
7237 | error = "Unsupported channel type requested"; | |
7238 | } | |
7239 | ||
7240 | c->remoteid = remid; | |
7241 | c->halfopen = FALSE; | |
7242 | if (error) { | |
7243 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
7244 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
7245 | ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED); | |
7246 | ssh2_pkt_addstring(pktout, error); | |
7247 | ssh2_pkt_addstring(pktout, "en"); /* language tag */ | |
7248 | ssh2_pkt_send(ssh, pktout); | |
7249 | logeventf(ssh, "Rejected channel open: %s", error); | |
7250 | sfree(c); | |
7251 | } else { | |
7252 | ssh2_channel_init(c); | |
7253 | c->v.v2.remwindow = winsize; | |
7254 | c->v.v2.remmaxpkt = pktsize; | |
7255 | add234(ssh->channels, c); | |
7256 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
7257 | ssh2_pkt_adduint32(pktout, c->remoteid); | |
7258 | ssh2_pkt_adduint32(pktout, c->localid); | |
7259 | ssh2_pkt_adduint32(pktout, c->v.v2.locwindow); | |
7260 | ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ | |
7261 | ssh2_pkt_send(ssh, pktout); | |
7262 | } | |
7263 | } | |
7264 | ||
7265 | /* | |
7266 | * Buffer banner messages for later display at some convenient point, | |
7267 | * if we're going to display them. | |
7268 | */ | |
7269 | static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin) | |
7270 | { | |
7271 | /* Arbitrary limit to prevent unbounded inflation of buffer */ | |
7272 | if (ssh->cfg.ssh_show_banner && | |
7273 | bufchain_size(&ssh->banner) <= 131072) { | |
7274 | char *banner = NULL; | |
7275 | int size = 0; | |
7276 | ssh_pkt_getstring(pktin, &banner, &size); | |
7277 | if (banner) | |
7278 | bufchain_add(&ssh->banner, banner, size); | |
7279 | } | |
7280 | } | |
7281 | ||
7282 | /* Helper function to deal with sending tty modes for "pty-req" */ | |
7283 | static void ssh2_send_ttymode(void *data, char *mode, char *val) | |
7284 | { | |
7285 | struct Packet *pktout = (struct Packet *)data; | |
7286 | int i = 0; | |
7287 | unsigned int arg = 0; | |
7288 | while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; | |
7289 | if (i == lenof(ssh_ttymodes)) return; | |
7290 | switch (ssh_ttymodes[i].type) { | |
7291 | case TTY_OP_CHAR: | |
7292 | arg = ssh_tty_parse_specchar(val); | |
7293 | break; | |
7294 | case TTY_OP_BOOL: | |
7295 | arg = ssh_tty_parse_boolean(val); | |
7296 | break; | |
7297 | } | |
7298 | ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); | |
7299 | ssh2_pkt_adduint32(pktout, arg); | |
7300 | } | |
7301 | ||
7302 | /* | |
7303 | * Handle the SSH-2 userauth and connection layers. | |
7304 | */ | |
7305 | static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, | |
7306 | struct Packet *pktin) | |
7307 | { | |
7308 | struct do_ssh2_authconn_state { | |
7309 | enum { | |
7310 | AUTH_TYPE_NONE, | |
7311 | AUTH_TYPE_PUBLICKEY, | |
7312 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, | |
7313 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, | |
7314 | AUTH_TYPE_PASSWORD, | |
7315 | AUTH_TYPE_GSSAPI, | |
7316 | AUTH_TYPE_KEYBOARD_INTERACTIVE, | |
7317 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET | |
7318 | } type; | |
7319 | int done_service_req; | |
7320 | int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; | |
7321 | int tried_pubkey_config, done_agent; | |
7322 | #ifndef NO_GSSAPI | |
7323 | int can_gssapi; | |
7324 | int tried_gssapi; | |
7325 | #endif | |
7326 | int kbd_inter_refused; | |
7327 | int we_are_in, userauth_success; | |
7328 | prompts_t *cur_prompt; | |
7329 | int num_prompts; | |
7330 | char username[100]; | |
7331 | char *password; | |
7332 | int got_username; | |
7333 | void *publickey_blob; | |
7334 | int publickey_bloblen; | |
7335 | int publickey_encrypted; | |
7336 | char *publickey_algorithm; | |
7337 | char *publickey_comment; | |
7338 | unsigned char agent_request[5], *agent_response, *agentp; | |
7339 | int agent_responselen; | |
7340 | unsigned char *pkblob_in_agent; | |
7341 | int keyi, nkeys; | |
7342 | char *pkblob, *alg, *commentp; | |
7343 | int pklen, alglen, commentlen; | |
7344 | int siglen, retlen, len; | |
7345 | char *q, *agentreq, *ret; | |
7346 | int try_send; | |
7347 | int num_env, env_left, env_ok; | |
7348 | struct Packet *pktout; | |
7349 | #ifndef NO_GSSAPI | |
7350 | struct ssh_gss_library *gsslib; | |
7351 | Ssh_gss_ctx gss_ctx; | |
7352 | Ssh_gss_buf gss_buf; | |
7353 | Ssh_gss_buf gss_rcvtok, gss_sndtok; | |
7354 | Ssh_gss_name gss_srv_name; | |
7355 | Ssh_gss_stat gss_stat; | |
7356 | #endif | |
7357 | }; | |
7358 | crState(do_ssh2_authconn_state); | |
7359 | ||
7360 | crBegin(ssh->do_ssh2_authconn_crstate); | |
7361 | ||
7362 | s->done_service_req = FALSE; | |
7363 | s->we_are_in = s->userauth_success = FALSE; | |
7364 | #ifndef NO_GSSAPI | |
7365 | s->tried_gssapi = FALSE; | |
7366 | #endif | |
7367 | ||
7368 | if (!ssh->cfg.ssh_no_userauth) { | |
7369 | /* | |
7370 | * Request userauth protocol, and await a response to it. | |
7371 | */ | |
7372 | s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); | |
7373 | ssh2_pkt_addstring(s->pktout, "ssh-userauth"); | |
7374 | ssh2_pkt_send(ssh, s->pktout); | |
7375 | crWaitUntilV(pktin); | |
7376 | if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) | |
7377 | s->done_service_req = TRUE; | |
7378 | } | |
7379 | if (!s->done_service_req) { | |
7380 | /* | |
7381 | * Request connection protocol directly, without authentication. | |
7382 | */ | |
7383 | s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); | |
7384 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
7385 | ssh2_pkt_send(ssh, s->pktout); | |
7386 | crWaitUntilV(pktin); | |
7387 | if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) { | |
7388 | s->we_are_in = TRUE; /* no auth required */ | |
7389 | } else { | |
7390 | bombout(("Server refused service request")); | |
7391 | crStopV; | |
7392 | } | |
7393 | } | |
7394 | ||
7395 | /* Arrange to be able to deal with any BANNERs that come in. | |
7396 | * (We do this now as packets may come in during the next bit.) */ | |
7397 | bufchain_init(&ssh->banner); | |
7398 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = | |
7399 | ssh2_msg_userauth_banner; | |
7400 | ||
7401 | /* | |
7402 | * Misc one-time setup for authentication. | |
7403 | */ | |
7404 | s->publickey_blob = NULL; | |
7405 | if (!s->we_are_in) { | |
7406 | ||
7407 | /* | |
7408 | * Load the public half of any configured public key file | |
7409 | * for later use. | |
7410 | */ | |
7411 | if (!filename_is_null(ssh->cfg.keyfile)) { | |
7412 | int keytype; | |
7413 | logeventf(ssh, "Reading private key file \"%.150s\"", | |
7414 | filename_to_str(&ssh->cfg.keyfile)); | |
7415 | keytype = key_type(&ssh->cfg.keyfile); | |
7416 | if (keytype == SSH_KEYTYPE_SSH2) { | |
7417 | const char *error; | |
7418 | s->publickey_blob = | |
7419 | ssh2_userkey_loadpub(&ssh->cfg.keyfile, | |
7420 | &s->publickey_algorithm, | |
7421 | &s->publickey_bloblen, | |
7422 | &s->publickey_comment, &error); | |
7423 | if (s->publickey_blob) { | |
7424 | s->publickey_encrypted = | |
7425 | ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL); | |
7426 | } else { | |
7427 | char *msgbuf; | |
7428 | logeventf(ssh, "Unable to load private key (%s)", | |
7429 | error); | |
7430 | msgbuf = dupprintf("Unable to load private key file " | |
7431 | "\"%.150s\" (%s)\r\n", | |
7432 | filename_to_str(&ssh->cfg.keyfile), | |
7433 | error); | |
7434 | c_write_str(ssh, msgbuf); | |
7435 | sfree(msgbuf); | |
7436 | } | |
7437 | } else { | |
7438 | char *msgbuf; | |
7439 | logeventf(ssh, "Unable to use this key file (%s)", | |
7440 | key_type_to_str(keytype)); | |
7441 | msgbuf = dupprintf("Unable to use key file \"%.150s\"" | |
7442 | " (%s)\r\n", | |
7443 | filename_to_str(&ssh->cfg.keyfile), | |
7444 | key_type_to_str(keytype)); | |
7445 | c_write_str(ssh, msgbuf); | |
7446 | sfree(msgbuf); | |
7447 | s->publickey_blob = NULL; | |
7448 | } | |
7449 | } | |
7450 | ||
7451 | /* | |
7452 | * Find out about any keys Pageant has (but if there's a | |
7453 | * public key configured, filter out all others). | |
7454 | */ | |
7455 | s->nkeys = 0; | |
7456 | s->agent_response = NULL; | |
7457 | s->pkblob_in_agent = NULL; | |
7458 | if (ssh->cfg.tryagent && agent_exists()) { | |
7459 | ||
7460 | void *r; | |
7461 | ||
7462 | logevent("Pageant is running. Requesting keys."); | |
7463 | ||
7464 | /* Request the keys held by the agent. */ | |
7465 | PUT_32BIT(s->agent_request, 1); | |
7466 | s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; | |
7467 | if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen, | |
7468 | ssh_agent_callback, ssh)) { | |
7469 | do { | |
7470 | crReturnV; | |
7471 | if (pktin) { | |
7472 | bombout(("Unexpected data from server while" | |
7473 | " waiting for agent response")); | |
7474 | crStopV; | |
7475 | } | |
7476 | } while (pktin || inlen > 0); | |
7477 | r = ssh->agent_response; | |
7478 | s->agent_responselen = ssh->agent_response_len; | |
7479 | } | |
7480 | s->agent_response = (unsigned char *) r; | |
7481 | if (s->agent_response && s->agent_responselen >= 5 && | |
7482 | s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { | |
7483 | int keyi; | |
7484 | unsigned char *p; | |
7485 | p = s->agent_response + 5; | |
7486 | s->nkeys = GET_32BIT(p); | |
7487 | p += 4; | |
7488 | logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); | |
7489 | if (s->publickey_blob) { | |
7490 | /* See if configured key is in agent. */ | |
7491 | for (keyi = 0; keyi < s->nkeys; keyi++) { | |
7492 | s->pklen = GET_32BIT(p); | |
7493 | if (s->pklen == s->publickey_bloblen && | |
7494 | !memcmp(p+4, s->publickey_blob, | |
7495 | s->publickey_bloblen)) { | |
7496 | logeventf(ssh, "Pageant key #%d matches " | |
7497 | "configured key file", keyi); | |
7498 | s->keyi = keyi; | |
7499 | s->pkblob_in_agent = p; | |
7500 | break; | |
7501 | } | |
7502 | p += 4 + s->pklen; | |
7503 | p += GET_32BIT(p) + 4; /* comment */ | |
7504 | } | |
7505 | if (!s->pkblob_in_agent) { | |
7506 | logevent("Configured key file not in Pageant"); | |
7507 | s->nkeys = 0; | |
7508 | } | |
7509 | } | |
7510 | } else { | |
7511 | logevent("Failed to get reply from Pageant"); | |
7512 | } | |
7513 | } | |
7514 | ||
7515 | } | |
7516 | ||
7517 | /* | |
7518 | * We repeat this whole loop, including the username prompt, | |
7519 | * until we manage a successful authentication. If the user | |
7520 | * types the wrong _password_, they can be sent back to the | |
7521 | * beginning to try another username, if this is configured on. | |
7522 | * (If they specify a username in the config, they are never | |
7523 | * asked, even if they do give a wrong password.) | |
7524 | * | |
7525 | * I think this best serves the needs of | |
7526 | * | |
7527 | * - the people who have no configuration, no keys, and just | |
7528 | * want to try repeated (username,password) pairs until they | |
7529 | * type both correctly | |
7530 | * | |
7531 | * - people who have keys and configuration but occasionally | |
7532 | * need to fall back to passwords | |
7533 | * | |
7534 | * - people with a key held in Pageant, who might not have | |
7535 | * logged in to a particular machine before; so they want to | |
7536 | * type a username, and then _either_ their key will be | |
7537 | * accepted, _or_ they will type a password. If they mistype | |
7538 | * the username they will want to be able to get back and | |
7539 | * retype it! | |
7540 | */ | |
7541 | s->username[0] = '\0'; | |
7542 | s->got_username = FALSE; | |
7543 | while (!s->we_are_in) { | |
7544 | /* | |
7545 | * Get a username. | |
7546 | */ | |
7547 | if (s->got_username && !ssh->cfg.change_username) { | |
7548 | /* | |
7549 | * We got a username last time round this loop, and | |
7550 | * with change_username turned off we don't try to get | |
7551 | * it again. | |
7552 | */ | |
7553 | } else if (!get_remote_username(&ssh->cfg, s->username, | |
7554 | sizeof(s->username))) { | |
7555 | int ret; /* need not be kept over crReturn */ | |
7556 | s->cur_prompt = new_prompts(ssh->frontend); | |
7557 | s->cur_prompt->to_server = TRUE; | |
7558 | s->cur_prompt->name = dupstr("SSH login name"); | |
7559 | add_prompt(s->cur_prompt, dupstr("login as: "), TRUE, | |
7560 | lenof(s->username)); | |
7561 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
7562 | while (ret < 0) { | |
7563 | ssh->send_ok = 1; | |
7564 | crWaitUntilV(!pktin); | |
7565 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
7566 | ssh->send_ok = 0; | |
7567 | } | |
7568 | if (!ret) { | |
7569 | /* | |
7570 | * get_userpass_input() failed to get a username. | |
7571 | * Terminate. | |
7572 | */ | |
7573 | free_prompts(s->cur_prompt); | |
7574 | ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); | |
7575 | crStopV; | |
7576 | } | |
7577 | memcpy(s->username, s->cur_prompt->prompts[0]->result, | |
7578 | lenof(s->username)); | |
7579 | free_prompts(s->cur_prompt); | |
7580 | } else { | |
7581 | char *stuff; | |
7582 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { | |
7583 | stuff = dupprintf("Using username \"%s\".\r\n", s->username); | |
7584 | c_write_str(ssh, stuff); | |
7585 | sfree(stuff); | |
7586 | } | |
7587 | } | |
7588 | s->got_username = TRUE; | |
7589 | ||
7590 | /* | |
7591 | * Send an authentication request using method "none": (a) | |
7592 | * just in case it succeeds, and (b) so that we know what | |
7593 | * authentication methods we can usefully try next. | |
7594 | */ | |
7595 | ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; | |
7596 | ||
7597 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
7598 | ssh2_pkt_addstring(s->pktout, s->username); | |
7599 | ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */ | |
7600 | ssh2_pkt_addstring(s->pktout, "none"); /* method */ | |
7601 | ssh2_pkt_send(ssh, s->pktout); | |
7602 | s->type = AUTH_TYPE_NONE; | |
7603 | s->gotit = FALSE; | |
7604 | s->we_are_in = FALSE; | |
7605 | ||
7606 | s->tried_pubkey_config = FALSE; | |
7607 | s->kbd_inter_refused = FALSE; | |
7608 | ||
7609 | /* Reset agent request state. */ | |
7610 | s->done_agent = FALSE; | |
7611 | if (s->agent_response) { | |
7612 | if (s->pkblob_in_agent) { | |
7613 | s->agentp = s->pkblob_in_agent; | |
7614 | } else { | |
7615 | s->agentp = s->agent_response + 5 + 4; | |
7616 | s->keyi = 0; | |
7617 | } | |
7618 | } | |
7619 | ||
7620 | while (1) { | |
7621 | char *methods = NULL; | |
7622 | int methlen = 0; | |
7623 | ||
7624 | /* | |
7625 | * Wait for the result of the last authentication request. | |
7626 | */ | |
7627 | if (!s->gotit) | |
7628 | crWaitUntilV(pktin); | |
7629 | /* | |
7630 | * Now is a convenient point to spew any banner material | |
7631 | * that we've accumulated. (This should ensure that when | |
7632 | * we exit the auth loop, we haven't any left to deal | |
7633 | * with.) | |
7634 | */ | |
7635 | { | |
7636 | int size = bufchain_size(&ssh->banner); | |
7637 | /* | |
7638 | * Don't show the banner if we're operating in | |
7639 | * non-verbose non-interactive mode. (It's probably | |
7640 | * a script, which means nobody will read the | |
7641 | * banner _anyway_, and moreover the printing of | |
7642 | * the banner will screw up processing on the | |
7643 | * output of (say) plink.) | |
7644 | */ | |
7645 | if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) { | |
7646 | char *banner = snewn(size, char); | |
7647 | bufchain_fetch(&ssh->banner, banner, size); | |
7648 | c_write_untrusted(ssh, banner, size); | |
7649 | sfree(banner); | |
7650 | } | |
7651 | bufchain_clear(&ssh->banner); | |
7652 | } | |
7653 | if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) { | |
7654 | logevent("Access granted"); | |
7655 | s->we_are_in = s->userauth_success = TRUE; | |
7656 | break; | |
7657 | } | |
7658 | ||
7659 | if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) { | |
7660 | bombout(("Strange packet received during authentication: " | |
7661 | "type %d", pktin->type)); | |
7662 | crStopV; | |
7663 | } | |
7664 | ||
7665 | s->gotit = FALSE; | |
7666 | ||
7667 | /* | |
7668 | * OK, we're now sitting on a USERAUTH_FAILURE message, so | |
7669 | * we can look at the string in it and know what we can | |
7670 | * helpfully try next. | |
7671 | */ | |
7672 | if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) { | |
7673 | ssh_pkt_getstring(pktin, &methods, &methlen); | |
7674 | if (!ssh2_pkt_getbool(pktin)) { | |
7675 | /* | |
7676 | * We have received an unequivocal Access | |
7677 | * Denied. This can translate to a variety of | |
7678 | * messages: | |
7679 | * | |
7680 | * - if we'd just tried "none" authentication, | |
7681 | * it's not worth printing anything at all | |
7682 | * | |
7683 | * - if we'd just tried a public key _offer_, | |
7684 | * the message should be "Server refused our | |
7685 | * key" (or no message at all if the key | |
7686 | * came from Pageant) | |
7687 | * | |
7688 | * - if we'd just tried anything else, the | |
7689 | * message really should be "Access denied". | |
7690 | * | |
7691 | * Additionally, if we'd just tried password | |
7692 | * authentication, we should break out of this | |
7693 | * whole loop so as to go back to the username | |
7694 | * prompt (iff we're configured to allow | |
7695 | * username change attempts). | |
7696 | */ | |
7697 | if (s->type == AUTH_TYPE_NONE) { | |
7698 | /* do nothing */ | |
7699 | } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || | |
7700 | s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { | |
7701 | if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) | |
7702 | c_write_str(ssh, "Server refused our key\r\n"); | |
7703 | logevent("Server refused public key"); | |
7704 | } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { | |
7705 | /* server declined keyboard-interactive; ignore */ | |
7706 | } else { | |
7707 | c_write_str(ssh, "Access denied\r\n"); | |
7708 | logevent("Access denied"); | |
7709 | if (s->type == AUTH_TYPE_PASSWORD && | |
7710 | ssh->cfg.change_username) { | |
7711 | /* XXX perhaps we should allow | |
7712 | * keyboard-interactive to do this too? */ | |
7713 | s->we_are_in = FALSE; | |
7714 | break; | |
7715 | } | |
7716 | } | |
7717 | } else { | |
7718 | c_write_str(ssh, "Further authentication required\r\n"); | |
7719 | logevent("Further authentication required"); | |
7720 | } | |
7721 | ||
7722 | s->can_pubkey = | |
7723 | in_commasep_string("publickey", methods, methlen); | |
7724 | s->can_passwd = | |
7725 | in_commasep_string("password", methods, methlen); | |
7726 | s->can_keyb_inter = ssh->cfg.try_ki_auth && | |
7727 | in_commasep_string("keyboard-interactive", methods, methlen); | |
7728 | #ifndef NO_GSSAPI | |
7729 | if (!ssh->gsslibs) | |
7730 | ssh->gsslibs = ssh_gss_setup(&ssh->cfg); | |
7731 | s->can_gssapi = ssh->cfg.try_gssapi_auth && | |
7732 | in_commasep_string("gssapi-with-mic", methods, methlen) && | |
7733 | ssh->gsslibs->nlibraries > 0; | |
7734 | #endif | |
7735 | } | |
7736 | ||
7737 | ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; | |
7738 | ||
7739 | if (s->can_pubkey && !s->done_agent && s->nkeys) { | |
7740 | ||
7741 | /* | |
7742 | * Attempt public-key authentication using a key from Pageant. | |
7743 | */ | |
7744 | ||
7745 | ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; | |
7746 | ||
7747 | logeventf(ssh, "Trying Pageant key #%d", s->keyi); | |
7748 | ||
7749 | /* Unpack key from agent response */ | |
7750 | s->pklen = GET_32BIT(s->agentp); | |
7751 | s->agentp += 4; | |
7752 | s->pkblob = (char *)s->agentp; | |
7753 | s->agentp += s->pklen; | |
7754 | s->alglen = GET_32BIT(s->pkblob); | |
7755 | s->alg = s->pkblob + 4; | |
7756 | s->commentlen = GET_32BIT(s->agentp); | |
7757 | s->agentp += 4; | |
7758 | s->commentp = (char *)s->agentp; | |
7759 | s->agentp += s->commentlen; | |
7760 | /* s->agentp now points at next key, if any */ | |
7761 | ||
7762 | /* See if server will accept it */ | |
7763 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
7764 | ssh2_pkt_addstring(s->pktout, s->username); | |
7765 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
7766 | /* service requested */ | |
7767 | ssh2_pkt_addstring(s->pktout, "publickey"); | |
7768 | /* method */ | |
7769 | ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ | |
7770 | ssh2_pkt_addstring_start(s->pktout); | |
7771 | ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); | |
7772 | ssh2_pkt_addstring_start(s->pktout); | |
7773 | ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); | |
7774 | ssh2_pkt_send(ssh, s->pktout); | |
7775 | s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET; | |
7776 | ||
7777 | crWaitUntilV(pktin); | |
7778 | if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { | |
7779 | ||
7780 | /* Offer of key refused. */ | |
7781 | s->gotit = TRUE; | |
7782 | ||
7783 | } else { | |
7784 | ||
7785 | void *vret; | |
7786 | ||
7787 | if (flags & FLAG_VERBOSE) { | |
7788 | c_write_str(ssh, "Authenticating with " | |
7789 | "public key \""); | |
7790 | c_write(ssh, s->commentp, s->commentlen); | |
7791 | c_write_str(ssh, "\" from agent\r\n"); | |
7792 | } | |
7793 | ||
7794 | /* | |
7795 | * Server is willing to accept the key. | |
7796 | * Construct a SIGN_REQUEST. | |
7797 | */ | |
7798 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
7799 | ssh2_pkt_addstring(s->pktout, s->username); | |
7800 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
7801 | /* service requested */ | |
7802 | ssh2_pkt_addstring(s->pktout, "publickey"); | |
7803 | /* method */ | |
7804 | ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */ | |
7805 | ssh2_pkt_addstring_start(s->pktout); | |
7806 | ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); | |
7807 | ssh2_pkt_addstring_start(s->pktout); | |
7808 | ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); | |
7809 | ||
7810 | /* Ask agent for signature. */ | |
7811 | s->siglen = s->pktout->length - 5 + 4 + | |
7812 | ssh->v2_session_id_len; | |
7813 | if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) | |
7814 | s->siglen -= 4; | |
7815 | s->len = 1; /* message type */ | |
7816 | s->len += 4 + s->pklen; /* key blob */ | |
7817 | s->len += 4 + s->siglen; /* data to sign */ | |
7818 | s->len += 4; /* flags */ | |
7819 | s->agentreq = snewn(4 + s->len, char); | |
7820 | PUT_32BIT(s->agentreq, s->len); | |
7821 | s->q = s->agentreq + 4; | |
7822 | *s->q++ = SSH2_AGENTC_SIGN_REQUEST; | |
7823 | PUT_32BIT(s->q, s->pklen); | |
7824 | s->q += 4; | |
7825 | memcpy(s->q, s->pkblob, s->pklen); | |
7826 | s->q += s->pklen; | |
7827 | PUT_32BIT(s->q, s->siglen); | |
7828 | s->q += 4; | |
7829 | /* Now the data to be signed... */ | |
7830 | if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { | |
7831 | PUT_32BIT(s->q, ssh->v2_session_id_len); | |
7832 | s->q += 4; | |
7833 | } | |
7834 | memcpy(s->q, ssh->v2_session_id, | |
7835 | ssh->v2_session_id_len); | |
7836 | s->q += ssh->v2_session_id_len; | |
7837 | memcpy(s->q, s->pktout->data + 5, | |
7838 | s->pktout->length - 5); | |
7839 | s->q += s->pktout->length - 5; | |
7840 | /* And finally the (zero) flags word. */ | |
7841 | PUT_32BIT(s->q, 0); | |
7842 | if (!agent_query(s->agentreq, s->len + 4, | |
7843 | &vret, &s->retlen, | |
7844 | ssh_agent_callback, ssh)) { | |
7845 | do { | |
7846 | crReturnV; | |
7847 | if (pktin) { | |
7848 | bombout(("Unexpected data from server" | |
7849 | " while waiting for agent" | |
7850 | " response")); | |
7851 | crStopV; | |
7852 | } | |
7853 | } while (pktin || inlen > 0); | |
7854 | vret = ssh->agent_response; | |
7855 | s->retlen = ssh->agent_response_len; | |
7856 | } | |
7857 | s->ret = vret; | |
7858 | sfree(s->agentreq); | |
7859 | if (s->ret) { | |
7860 | if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { | |
7861 | logevent("Sending Pageant's response"); | |
7862 | ssh2_add_sigblob(ssh, s->pktout, | |
7863 | s->pkblob, s->pklen, | |
7864 | s->ret + 9, | |
7865 | GET_32BIT(s->ret + 5)); | |
7866 | ssh2_pkt_send(ssh, s->pktout); | |
7867 | s->type = AUTH_TYPE_PUBLICKEY; | |
7868 | } else { | |
7869 | /* FIXME: less drastic response */ | |
7870 | bombout(("Pageant failed to answer challenge")); | |
7871 | crStopV; | |
7872 | } | |
7873 | } | |
7874 | } | |
7875 | ||
7876 | /* Do we have any keys left to try? */ | |
7877 | if (s->pkblob_in_agent) { | |
7878 | s->done_agent = TRUE; | |
7879 | s->tried_pubkey_config = TRUE; | |
7880 | } else { | |
7881 | s->keyi++; | |
7882 | if (s->keyi >= s->nkeys) | |
7883 | s->done_agent = TRUE; | |
7884 | } | |
7885 | ||
7886 | } else if (s->can_pubkey && s->publickey_blob && | |
7887 | !s->tried_pubkey_config) { | |
7888 | ||
7889 | struct ssh2_userkey *key; /* not live over crReturn */ | |
7890 | char *passphrase; /* not live over crReturn */ | |
7891 | ||
7892 | ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; | |
7893 | ||
7894 | s->tried_pubkey_config = TRUE; | |
7895 | ||
7896 | /* | |
7897 | * Try the public key supplied in the configuration. | |
7898 | * | |
7899 | * First, offer the public blob to see if the server is | |
7900 | * willing to accept it. | |
7901 | */ | |
7902 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
7903 | ssh2_pkt_addstring(s->pktout, s->username); | |
7904 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
7905 | /* service requested */ | |
7906 | ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ | |
7907 | ssh2_pkt_addbool(s->pktout, FALSE); | |
7908 | /* no signature included */ | |
7909 | ssh2_pkt_addstring(s->pktout, s->publickey_algorithm); | |
7910 | ssh2_pkt_addstring_start(s->pktout); | |
7911 | ssh2_pkt_addstring_data(s->pktout, | |
7912 | (char *)s->publickey_blob, | |
7913 | s->publickey_bloblen); | |
7914 | ssh2_pkt_send(ssh, s->pktout); | |
7915 | logevent("Offered public key"); | |
7916 | ||
7917 | crWaitUntilV(pktin); | |
7918 | if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { | |
7919 | /* Key refused. Give up. */ | |
7920 | s->gotit = TRUE; /* reconsider message next loop */ | |
7921 | s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; | |
7922 | continue; /* process this new message */ | |
7923 | } | |
7924 | logevent("Offer of public key accepted"); | |
7925 | ||
7926 | /* | |
7927 | * Actually attempt a serious authentication using | |
7928 | * the key. | |
7929 | */ | |
7930 | if (flags & FLAG_VERBOSE) { | |
7931 | c_write_str(ssh, "Authenticating with public key \""); | |
7932 | c_write_str(ssh, s->publickey_comment); | |
7933 | c_write_str(ssh, "\"\r\n"); | |
7934 | } | |
7935 | key = NULL; | |
7936 | while (!key) { | |
7937 | const char *error; /* not live over crReturn */ | |
7938 | if (s->publickey_encrypted) { | |
7939 | /* | |
7940 | * Get a passphrase from the user. | |
7941 | */ | |
7942 | int ret; /* need not be kept over crReturn */ | |
7943 | s->cur_prompt = new_prompts(ssh->frontend); | |
7944 | s->cur_prompt->to_server = FALSE; | |
7945 | s->cur_prompt->name = dupstr("SSH key passphrase"); | |
7946 | add_prompt(s->cur_prompt, | |
7947 | dupprintf("Passphrase for key \"%.100s\": ", | |
7948 | s->publickey_comment), | |
7949 | FALSE, SSH_MAX_PASSWORD_LEN); | |
7950 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
7951 | while (ret < 0) { | |
7952 | ssh->send_ok = 1; | |
7953 | crWaitUntilV(!pktin); | |
7954 | ret = get_userpass_input(s->cur_prompt, | |
7955 | in, inlen); | |
7956 | ssh->send_ok = 0; | |
7957 | } | |
7958 | if (!ret) { | |
7959 | /* Failed to get a passphrase. Terminate. */ | |
7960 | free_prompts(s->cur_prompt); | |
7961 | ssh_disconnect(ssh, NULL, | |
7962 | "Unable to authenticate", | |
7963 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, | |
7964 | TRUE); | |
7965 | crStopV; | |
7966 | } | |
7967 | passphrase = | |
7968 | dupstr(s->cur_prompt->prompts[0]->result); | |
7969 | free_prompts(s->cur_prompt); | |
7970 | } else { | |
7971 | passphrase = NULL; /* no passphrase needed */ | |
7972 | } | |
7973 | ||
7974 | /* | |
7975 | * Try decrypting the key. | |
7976 | */ | |
7977 | key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase, | |
7978 | &error); | |
7979 | if (passphrase) { | |
7980 | /* burn the evidence */ | |
7981 | memset(passphrase, 0, strlen(passphrase)); | |
7982 | sfree(passphrase); | |
7983 | } | |
7984 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { | |
7985 | if (passphrase && | |
7986 | (key == SSH2_WRONG_PASSPHRASE)) { | |
7987 | c_write_str(ssh, "Wrong passphrase\r\n"); | |
7988 | key = NULL; | |
7989 | /* and loop again */ | |
7990 | } else { | |
7991 | c_write_str(ssh, "Unable to load private key ("); | |
7992 | c_write_str(ssh, error); | |
7993 | c_write_str(ssh, ")\r\n"); | |
7994 | key = NULL; | |
7995 | break; /* try something else */ | |
7996 | } | |
7997 | } | |
7998 | } | |
7999 | ||
8000 | if (key) { | |
8001 | unsigned char *pkblob, *sigblob, *sigdata; | |
8002 | int pkblob_len, sigblob_len, sigdata_len; | |
8003 | int p; | |
8004 | ||
8005 | /* | |
8006 | * We have loaded the private key and the server | |
8007 | * has announced that it's willing to accept it. | |
8008 | * Hallelujah. Generate a signature and send it. | |
8009 | */ | |
8010 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
8011 | ssh2_pkt_addstring(s->pktout, s->username); | |
8012 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
8013 | /* service requested */ | |
8014 | ssh2_pkt_addstring(s->pktout, "publickey"); | |
8015 | /* method */ | |
8016 | ssh2_pkt_addbool(s->pktout, TRUE); | |
8017 | /* signature follows */ | |
8018 | ssh2_pkt_addstring(s->pktout, key->alg->name); | |
8019 | pkblob = key->alg->public_blob(key->data, | |
8020 | &pkblob_len); | |
8021 | ssh2_pkt_addstring_start(s->pktout); | |
8022 | ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, | |
8023 | pkblob_len); | |
8024 | ||
8025 | /* | |
8026 | * The data to be signed is: | |
8027 | * | |
8028 | * string session-id | |
8029 | * | |
8030 | * followed by everything so far placed in the | |
8031 | * outgoing packet. | |
8032 | */ | |
8033 | sigdata_len = s->pktout->length - 5 + 4 + | |
8034 | ssh->v2_session_id_len; | |
8035 | if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) | |
8036 | sigdata_len -= 4; | |
8037 | sigdata = snewn(sigdata_len, unsigned char); | |
8038 | p = 0; | |
8039 | if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { | |
8040 | PUT_32BIT(sigdata+p, ssh->v2_session_id_len); | |
8041 | p += 4; | |
8042 | } | |
8043 | memcpy(sigdata+p, ssh->v2_session_id, | |
8044 | ssh->v2_session_id_len); | |
8045 | p += ssh->v2_session_id_len; | |
8046 | memcpy(sigdata+p, s->pktout->data + 5, | |
8047 | s->pktout->length - 5); | |
8048 | p += s->pktout->length - 5; | |
8049 | assert(p == sigdata_len); | |
8050 | sigblob = key->alg->sign(key->data, (char *)sigdata, | |
8051 | sigdata_len, &sigblob_len); | |
8052 | ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len, | |
8053 | sigblob, sigblob_len); | |
8054 | sfree(pkblob); | |
8055 | sfree(sigblob); | |
8056 | sfree(sigdata); | |
8057 | ||
8058 | ssh2_pkt_send(ssh, s->pktout); | |
8059 | s->type = AUTH_TYPE_PUBLICKEY; | |
8060 | key->alg->freekey(key->data); | |
8061 | } | |
8062 | ||
8063 | #ifndef NO_GSSAPI | |
8064 | } else if (s->can_gssapi && !s->tried_gssapi) { | |
8065 | ||
8066 | /* GSSAPI Authentication */ | |
8067 | ||
8068 | int micoffset, len; | |
8069 | char *data; | |
8070 | Ssh_gss_buf mic; | |
8071 | s->type = AUTH_TYPE_GSSAPI; | |
8072 | s->tried_gssapi = TRUE; | |
8073 | s->gotit = TRUE; | |
8074 | ssh->pkt_actx = SSH2_PKTCTX_GSSAPI; | |
8075 | ||
8076 | /* | |
8077 | * Pick the highest GSS library on the preference | |
8078 | * list. | |
8079 | */ | |
8080 | { | |
8081 | int i, j; | |
8082 | s->gsslib = NULL; | |
8083 | for (i = 0; i < ngsslibs; i++) { | |
8084 | int want_id = ssh->cfg.ssh_gsslist[i]; | |
8085 | for (j = 0; j < ssh->gsslibs->nlibraries; j++) | |
8086 | if (ssh->gsslibs->libraries[j].id == want_id) { | |
8087 | s->gsslib = &ssh->gsslibs->libraries[j]; | |
8088 | goto got_gsslib; /* double break */ | |
8089 | } | |
8090 | } | |
8091 | got_gsslib: | |
8092 | /* | |
8093 | * We always expect to have found something in | |
8094 | * the above loop: we only came here if there | |
8095 | * was at least one viable GSS library, and the | |
8096 | * preference list should always mention | |
8097 | * everything and only change the order. | |
8098 | */ | |
8099 | assert(s->gsslib); | |
8100 | } | |
8101 | ||
8102 | if (s->gsslib->gsslogmsg) | |
8103 | logevent(s->gsslib->gsslogmsg); | |
8104 | ||
8105 | /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */ | |
8106 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
8107 | ssh2_pkt_addstring(s->pktout, s->username); | |
8108 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
8109 | ssh2_pkt_addstring(s->pktout, "gssapi-with-mic"); | |
8110 | ||
8111 | /* add mechanism info */ | |
8112 | s->gsslib->indicate_mech(s->gsslib, &s->gss_buf); | |
8113 | ||
8114 | /* number of GSSAPI mechanisms */ | |
8115 | ssh2_pkt_adduint32(s->pktout,1); | |
8116 | ||
8117 | /* length of OID + 2 */ | |
8118 | ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2); | |
8119 | ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE); | |
8120 | ||
8121 | /* length of OID */ | |
8122 | ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length); | |
8123 | ||
8124 | ssh_pkt_adddata(s->pktout, s->gss_buf.value, | |
8125 | s->gss_buf.length); | |
8126 | ssh2_pkt_send(ssh, s->pktout); | |
8127 | crWaitUntilV(pktin); | |
8128 | if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) { | |
8129 | logevent("GSSAPI authentication request refused"); | |
8130 | continue; | |
8131 | } | |
8132 | ||
8133 | /* check returned packet ... */ | |
8134 | ||
8135 | ssh_pkt_getstring(pktin, &data, &len); | |
8136 | s->gss_rcvtok.value = data; | |
8137 | s->gss_rcvtok.length = len; | |
8138 | if (s->gss_rcvtok.length != s->gss_buf.length + 2 || | |
8139 | ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE || | |
8140 | ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length || | |
8141 | memcmp((char *)s->gss_rcvtok.value + 2, | |
8142 | s->gss_buf.value,s->gss_buf.length) ) { | |
8143 | logevent("GSSAPI authentication - wrong response from server"); | |
8144 | continue; | |
8145 | } | |
8146 | ||
8147 | /* now start running */ | |
8148 | s->gss_stat = s->gsslib->import_name(s->gsslib, | |
8149 | ssh->fullhostname, | |
8150 | &s->gss_srv_name); | |
8151 | if (s->gss_stat != SSH_GSS_OK) { | |
8152 | if (s->gss_stat == SSH_GSS_BAD_HOST_NAME) | |
8153 | logevent("GSSAPI import name failed - Bad service name"); | |
8154 | else | |
8155 | logevent("GSSAPI import name failed"); | |
8156 | continue; | |
8157 | } | |
8158 | ||
8159 | /* fetch TGT into GSS engine */ | |
8160 | s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx); | |
8161 | ||
8162 | if (s->gss_stat != SSH_GSS_OK) { | |
8163 | logevent("GSSAPI authentication failed to get credentials"); | |
8164 | s->gsslib->release_name(s->gsslib, &s->gss_srv_name); | |
8165 | continue; | |
8166 | } | |
8167 | ||
8168 | /* initial tokens are empty */ | |
8169 | SSH_GSS_CLEAR_BUF(&s->gss_rcvtok); | |
8170 | SSH_GSS_CLEAR_BUF(&s->gss_sndtok); | |
8171 | ||
8172 | /* now enter the loop */ | |
8173 | do { | |
8174 | s->gss_stat = s->gsslib->init_sec_context | |
8175 | (s->gsslib, | |
8176 | &s->gss_ctx, | |
8177 | s->gss_srv_name, | |
8178 | ssh->cfg.gssapifwd, | |
8179 | &s->gss_rcvtok, | |
8180 | &s->gss_sndtok); | |
8181 | ||
8182 | if (s->gss_stat!=SSH_GSS_S_COMPLETE && | |
8183 | s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) { | |
8184 | logevent("GSSAPI authentication initialisation failed"); | |
8185 | ||
8186 | if (s->gsslib->display_status(s->gsslib, s->gss_ctx, | |
8187 | &s->gss_buf) == SSH_GSS_OK) { | |
8188 | logevent(s->gss_buf.value); | |
8189 | sfree(s->gss_buf.value); | |
8190 | } | |
8191 | ||
8192 | break; | |
8193 | } | |
8194 | logevent("GSSAPI authentication initialised"); | |
8195 | ||
8196 | /* Client and server now exchange tokens until GSSAPI | |
8197 | * no longer says CONTINUE_NEEDED */ | |
8198 | ||
8199 | if (s->gss_sndtok.length != 0) { | |
8200 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
8201 | ssh_pkt_addstring_start(s->pktout); | |
8202 | ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length); | |
8203 | ssh2_pkt_send(ssh, s->pktout); | |
8204 | s->gsslib->free_tok(s->gsslib, &s->gss_sndtok); | |
8205 | } | |
8206 | ||
8207 | if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) { | |
8208 | crWaitUntilV(pktin); | |
8209 | if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) { | |
8210 | logevent("GSSAPI authentication - bad server response"); | |
8211 | s->gss_stat = SSH_GSS_FAILURE; | |
8212 | break; | |
8213 | } | |
8214 | ssh_pkt_getstring(pktin, &data, &len); | |
8215 | s->gss_rcvtok.value = data; | |
8216 | s->gss_rcvtok.length = len; | |
8217 | } | |
8218 | } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED); | |
8219 | ||
8220 | if (s->gss_stat != SSH_GSS_OK) { | |
8221 | s->gsslib->release_name(s->gsslib, &s->gss_srv_name); | |
8222 | s->gsslib->release_cred(s->gsslib, &s->gss_ctx); | |
8223 | continue; | |
8224 | } | |
8225 | logevent("GSSAPI authentication loop finished OK"); | |
8226 | ||
8227 | /* Now send the MIC */ | |
8228 | ||
8229 | s->pktout = ssh2_pkt_init(0); | |
8230 | micoffset = s->pktout->length; | |
8231 | ssh_pkt_addstring_start(s->pktout); | |
8232 | ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len); | |
8233 | ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST); | |
8234 | ssh_pkt_addstring(s->pktout, s->username); | |
8235 | ssh_pkt_addstring(s->pktout, "ssh-connection"); | |
8236 | ssh_pkt_addstring(s->pktout, "gssapi-with-mic"); | |
8237 | ||
8238 | s->gss_buf.value = (char *)s->pktout->data + micoffset; | |
8239 | s->gss_buf.length = s->pktout->length - micoffset; | |
8240 | ||
8241 | s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic); | |
8242 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
8243 | ssh_pkt_addstring_start(s->pktout); | |
8244 | ssh_pkt_addstring_data(s->pktout, mic.value, mic.length); | |
8245 | ssh2_pkt_send(ssh, s->pktout); | |
8246 | s->gsslib->free_mic(s->gsslib, &mic); | |
8247 | ||
8248 | s->gotit = FALSE; | |
8249 | ||
8250 | s->gsslib->release_name(s->gsslib, &s->gss_srv_name); | |
8251 | s->gsslib->release_cred(s->gsslib, &s->gss_ctx); | |
8252 | continue; | |
8253 | #endif | |
8254 | } else if (s->can_keyb_inter && !s->kbd_inter_refused) { | |
8255 | ||
8256 | /* | |
8257 | * Keyboard-interactive authentication. | |
8258 | */ | |
8259 | ||
8260 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; | |
8261 | ||
8262 | ssh->pkt_actx = SSH2_PKTCTX_KBDINTER; | |
8263 | ||
8264 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
8265 | ssh2_pkt_addstring(s->pktout, s->username); | |
8266 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
8267 | /* service requested */ | |
8268 | ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); | |
8269 | /* method */ | |
8270 | ssh2_pkt_addstring(s->pktout, ""); /* lang */ | |
8271 | ssh2_pkt_addstring(s->pktout, ""); /* submethods */ | |
8272 | ssh2_pkt_send(ssh, s->pktout); | |
8273 | ||
8274 | crWaitUntilV(pktin); | |
8275 | if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) { | |
8276 | /* Server is not willing to do keyboard-interactive | |
8277 | * at all (or, bizarrely but legally, accepts the | |
8278 | * user without actually issuing any prompts). | |
8279 | * Give up on it entirely. */ | |
8280 | s->gotit = TRUE; | |
8281 | if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) | |
8282 | logevent("Keyboard-interactive authentication refused"); | |
8283 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; | |
8284 | s->kbd_inter_refused = TRUE; /* don't try it again */ | |
8285 | continue; | |
8286 | } | |
8287 | ||
8288 | /* | |
8289 | * Loop while the server continues to send INFO_REQUESTs. | |
8290 | */ | |
8291 | while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) { | |
8292 | ||
8293 | char *name, *inst, *lang; | |
8294 | int name_len, inst_len, lang_len; | |
8295 | int i; | |
8296 | ||
8297 | /* | |
8298 | * We've got a fresh USERAUTH_INFO_REQUEST. | |
8299 | * Get the preamble and start building a prompt. | |
8300 | */ | |
8301 | ssh_pkt_getstring(pktin, &name, &name_len); | |
8302 | ssh_pkt_getstring(pktin, &inst, &inst_len); | |
8303 | ssh_pkt_getstring(pktin, &lang, &lang_len); | |
8304 | s->cur_prompt = new_prompts(ssh->frontend); | |
8305 | s->cur_prompt->to_server = TRUE; | |
8306 | ||
8307 | /* | |
8308 | * Get any prompt(s) from the packet. | |
8309 | */ | |
8310 | s->num_prompts = ssh_pkt_getuint32(pktin); | |
8311 | for (i = 0; i < s->num_prompts; i++) { | |
8312 | char *prompt; | |
8313 | int prompt_len; | |
8314 | int echo; | |
8315 | static char noprompt[] = | |
8316 | "<server failed to send prompt>: "; | |
8317 | ||
8318 | ssh_pkt_getstring(pktin, &prompt, &prompt_len); | |
8319 | echo = ssh2_pkt_getbool(pktin); | |
8320 | if (!prompt_len) { | |
8321 | prompt = noprompt; | |
8322 | prompt_len = lenof(noprompt)-1; | |
8323 | } | |
8324 | add_prompt(s->cur_prompt, | |
8325 | dupprintf("%.*s", prompt_len, prompt), | |
8326 | echo, SSH_MAX_PASSWORD_LEN); | |
8327 | } | |
8328 | ||
8329 | if (name_len) { | |
8330 | /* FIXME: better prefix to distinguish from | |
8331 | * local prompts? */ | |
8332 | s->cur_prompt->name = | |
8333 | dupprintf("SSH server: %.*s", name_len, name); | |
8334 | s->cur_prompt->name_reqd = TRUE; | |
8335 | } else { | |
8336 | s->cur_prompt->name = | |
8337 | dupstr("SSH server authentication"); | |
8338 | s->cur_prompt->name_reqd = FALSE; | |
8339 | } | |
8340 | /* We add a prefix to try to make it clear that a prompt | |
8341 | * has come from the server. | |
8342 | * FIXME: ugly to print "Using..." in prompt _every_ | |
8343 | * time round. Can this be done more subtly? */ | |
8344 | /* Special case: for reasons best known to themselves, | |
8345 | * some servers send k-i requests with no prompts and | |
8346 | * nothing to display. Keep quiet in this case. */ | |
8347 | if (s->num_prompts || name_len || inst_len) { | |
8348 | s->cur_prompt->instruction = | |
8349 | dupprintf("Using keyboard-interactive authentication.%s%.*s", | |
8350 | inst_len ? "\n" : "", inst_len, inst); | |
8351 | s->cur_prompt->instr_reqd = TRUE; | |
8352 | } else { | |
8353 | s->cur_prompt->instr_reqd = FALSE; | |
8354 | } | |
8355 | ||
8356 | /* | |
8357 | * Display any instructions, and get the user's | |
8358 | * response(s). | |
8359 | */ | |
8360 | { | |
8361 | int ret; /* not live over crReturn */ | |
8362 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
8363 | while (ret < 0) { | |
8364 | ssh->send_ok = 1; | |
8365 | crWaitUntilV(!pktin); | |
8366 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
8367 | ssh->send_ok = 0; | |
8368 | } | |
8369 | if (!ret) { | |
8370 | /* | |
8371 | * Failed to get responses. Terminate. | |
8372 | */ | |
8373 | free_prompts(s->cur_prompt); | |
8374 | ssh_disconnect(ssh, NULL, "Unable to authenticate", | |
8375 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, | |
8376 | TRUE); | |
8377 | crStopV; | |
8378 | } | |
8379 | } | |
8380 | ||
8381 | /* | |
8382 | * Send the response(s) to the server. | |
8383 | */ | |
8384 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
8385 | ssh2_pkt_adduint32(s->pktout, s->num_prompts); | |
8386 | for (i=0; i < s->num_prompts; i++) { | |
8387 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); | |
8388 | ssh2_pkt_addstring(s->pktout, | |
8389 | s->cur_prompt->prompts[i]->result); | |
8390 | end_log_omission(ssh, s->pktout); | |
8391 | } | |
8392 | ssh2_pkt_send_with_padding(ssh, s->pktout, 256); | |
8393 | ||
8394 | /* | |
8395 | * Get the next packet in case it's another | |
8396 | * INFO_REQUEST. | |
8397 | */ | |
8398 | crWaitUntilV(pktin); | |
8399 | ||
8400 | } | |
8401 | ||
8402 | /* | |
8403 | * We should have SUCCESS or FAILURE now. | |
8404 | */ | |
8405 | s->gotit = TRUE; | |
8406 | ||
8407 | } else if (s->can_passwd) { | |
8408 | ||
8409 | /* | |
8410 | * Plain old password authentication. | |
8411 | */ | |
8412 | int ret; /* not live over crReturn */ | |
8413 | int changereq_first_time; /* not live over crReturn */ | |
8414 | ||
8415 | ssh->pkt_actx = SSH2_PKTCTX_PASSWORD; | |
8416 | ||
8417 | s->cur_prompt = new_prompts(ssh->frontend); | |
8418 | s->cur_prompt->to_server = TRUE; | |
8419 | s->cur_prompt->name = dupstr("SSH password"); | |
8420 | add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ", | |
8421 | s->username, | |
8422 | ssh->savedhost), | |
8423 | FALSE, SSH_MAX_PASSWORD_LEN); | |
8424 | ||
8425 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
8426 | while (ret < 0) { | |
8427 | ssh->send_ok = 1; | |
8428 | crWaitUntilV(!pktin); | |
8429 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
8430 | ssh->send_ok = 0; | |
8431 | } | |
8432 | if (!ret) { | |
8433 | /* | |
8434 | * Failed to get responses. Terminate. | |
8435 | */ | |
8436 | free_prompts(s->cur_prompt); | |
8437 | ssh_disconnect(ssh, NULL, "Unable to authenticate", | |
8438 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, | |
8439 | TRUE); | |
8440 | crStopV; | |
8441 | } | |
8442 | /* | |
8443 | * Squirrel away the password. (We may need it later if | |
8444 | * asked to change it.) | |
8445 | */ | |
8446 | s->password = dupstr(s->cur_prompt->prompts[0]->result); | |
8447 | free_prompts(s->cur_prompt); | |
8448 | ||
8449 | /* | |
8450 | * Send the password packet. | |
8451 | * | |
8452 | * We pad out the password packet to 256 bytes to make | |
8453 | * it harder for an attacker to find the length of the | |
8454 | * user's password. | |
8455 | * | |
8456 | * Anyone using a password longer than 256 bytes | |
8457 | * probably doesn't have much to worry about from | |
8458 | * people who find out how long their password is! | |
8459 | */ | |
8460 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
8461 | ssh2_pkt_addstring(s->pktout, s->username); | |
8462 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
8463 | /* service requested */ | |
8464 | ssh2_pkt_addstring(s->pktout, "password"); | |
8465 | ssh2_pkt_addbool(s->pktout, FALSE); | |
8466 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); | |
8467 | ssh2_pkt_addstring(s->pktout, s->password); | |
8468 | end_log_omission(ssh, s->pktout); | |
8469 | ssh2_pkt_send_with_padding(ssh, s->pktout, 256); | |
8470 | logevent("Sent password"); | |
8471 | s->type = AUTH_TYPE_PASSWORD; | |
8472 | ||
8473 | /* | |
8474 | * Wait for next packet, in case it's a password change | |
8475 | * request. | |
8476 | */ | |
8477 | crWaitUntilV(pktin); | |
8478 | changereq_first_time = TRUE; | |
8479 | ||
8480 | while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { | |
8481 | ||
8482 | /* | |
8483 | * We're being asked for a new password | |
8484 | * (perhaps not for the first time). | |
8485 | * Loop until the server accepts it. | |
8486 | */ | |
8487 | ||
8488 | int got_new = FALSE; /* not live over crReturn */ | |
8489 | char *prompt; /* not live over crReturn */ | |
8490 | int prompt_len; /* not live over crReturn */ | |
8491 | ||
8492 | { | |
8493 | char *msg; | |
8494 | if (changereq_first_time) | |
8495 | msg = "Server requested password change"; | |
8496 | else | |
8497 | msg = "Server rejected new password"; | |
8498 | logevent(msg); | |
8499 | c_write_str(ssh, msg); | |
8500 | c_write_str(ssh, "\r\n"); | |
8501 | } | |
8502 | ||
8503 | ssh_pkt_getstring(pktin, &prompt, &prompt_len); | |
8504 | ||
8505 | s->cur_prompt = new_prompts(ssh->frontend); | |
8506 | s->cur_prompt->to_server = TRUE; | |
8507 | s->cur_prompt->name = dupstr("New SSH password"); | |
8508 | s->cur_prompt->instruction = | |
8509 | dupprintf("%.*s", prompt_len, prompt); | |
8510 | s->cur_prompt->instr_reqd = TRUE; | |
8511 | /* | |
8512 | * There's no explicit requirement in the protocol | |
8513 | * for the "old" passwords in the original and | |
8514 | * password-change messages to be the same, and | |
8515 | * apparently some Cisco kit supports password change | |
8516 | * by the user entering a blank password originally | |
8517 | * and the real password subsequently, so, | |
8518 | * reluctantly, we prompt for the old password again. | |
8519 | * | |
8520 | * (On the other hand, some servers don't even bother | |
8521 | * to check this field.) | |
8522 | */ | |
8523 | add_prompt(s->cur_prompt, | |
8524 | dupstr("Current password (blank for previously entered password): "), | |
8525 | FALSE, SSH_MAX_PASSWORD_LEN); | |
8526 | add_prompt(s->cur_prompt, dupstr("Enter new password: "), | |
8527 | FALSE, SSH_MAX_PASSWORD_LEN); | |
8528 | add_prompt(s->cur_prompt, dupstr("Confirm new password: "), | |
8529 | FALSE, SSH_MAX_PASSWORD_LEN); | |
8530 | ||
8531 | /* | |
8532 | * Loop until the user manages to enter the same | |
8533 | * password twice. | |
8534 | */ | |
8535 | while (!got_new) { | |
8536 | ||
8537 | ret = get_userpass_input(s->cur_prompt, NULL, 0); | |
8538 | while (ret < 0) { | |
8539 | ssh->send_ok = 1; | |
8540 | crWaitUntilV(!pktin); | |
8541 | ret = get_userpass_input(s->cur_prompt, in, inlen); | |
8542 | ssh->send_ok = 0; | |
8543 | } | |
8544 | if (!ret) { | |
8545 | /* | |
8546 | * Failed to get responses. Terminate. | |
8547 | */ | |
8548 | /* burn the evidence */ | |
8549 | free_prompts(s->cur_prompt); | |
8550 | memset(s->password, 0, strlen(s->password)); | |
8551 | sfree(s->password); | |
8552 | ssh_disconnect(ssh, NULL, "Unable to authenticate", | |
8553 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, | |
8554 | TRUE); | |
8555 | crStopV; | |
8556 | } | |
8557 | ||
8558 | /* | |
8559 | * If the user specified a new original password | |
8560 | * (IYSWIM), overwrite any previously specified | |
8561 | * one. | |
8562 | * (A side effect is that the user doesn't have to | |
8563 | * re-enter it if they louse up the new password.) | |
8564 | */ | |
8565 | if (s->cur_prompt->prompts[0]->result[0]) { | |
8566 | memset(s->password, 0, strlen(s->password)); | |
8567 | /* burn the evidence */ | |
8568 | sfree(s->password); | |
8569 | s->password = | |
8570 | dupstr(s->cur_prompt->prompts[0]->result); | |
8571 | } | |
8572 | ||
8573 | /* | |
8574 | * Check the two new passwords match. | |
8575 | */ | |
8576 | got_new = (strcmp(s->cur_prompt->prompts[1]->result, | |
8577 | s->cur_prompt->prompts[2]->result) | |
8578 | == 0); | |
8579 | if (!got_new) | |
8580 | /* They don't. Silly user. */ | |
8581 | c_write_str(ssh, "Passwords do not match\r\n"); | |
8582 | ||
8583 | } | |
8584 | ||
8585 | /* | |
8586 | * Send the new password (along with the old one). | |
8587 | * (see above for padding rationale) | |
8588 | */ | |
8589 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); | |
8590 | ssh2_pkt_addstring(s->pktout, s->username); | |
8591 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); | |
8592 | /* service requested */ | |
8593 | ssh2_pkt_addstring(s->pktout, "password"); | |
8594 | ssh2_pkt_addbool(s->pktout, TRUE); | |
8595 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); | |
8596 | ssh2_pkt_addstring(s->pktout, s->password); | |
8597 | ssh2_pkt_addstring(s->pktout, | |
8598 | s->cur_prompt->prompts[1]->result); | |
8599 | free_prompts(s->cur_prompt); | |
8600 | end_log_omission(ssh, s->pktout); | |
8601 | ssh2_pkt_send_with_padding(ssh, s->pktout, 256); | |
8602 | logevent("Sent new password"); | |
8603 | ||
8604 | /* | |
8605 | * Now see what the server has to say about it. | |
8606 | * (If it's CHANGEREQ again, it's not happy with the | |
8607 | * new password.) | |
8608 | */ | |
8609 | crWaitUntilV(pktin); | |
8610 | changereq_first_time = FALSE; | |
8611 | ||
8612 | } | |
8613 | ||
8614 | /* | |
8615 | * We need to reexamine the current pktin at the top | |
8616 | * of the loop. Either: | |
8617 | * - we weren't asked to change password at all, in | |
8618 | * which case it's a SUCCESS or FAILURE with the | |
8619 | * usual meaning | |
8620 | * - we sent a new password, and the server was | |
8621 | * either OK with it (SUCCESS or FAILURE w/partial | |
8622 | * success) or unhappy with the _old_ password | |
8623 | * (FAILURE w/o partial success) | |
8624 | * In any of these cases, we go back to the top of | |
8625 | * the loop and start again. | |
8626 | */ | |
8627 | s->gotit = TRUE; | |
8628 | ||
8629 | /* | |
8630 | * We don't need the old password any more, in any | |
8631 | * case. Burn the evidence. | |
8632 | */ | |
8633 | memset(s->password, 0, strlen(s->password)); | |
8634 | sfree(s->password); | |
8635 | ||
8636 | } else { | |
8637 | char *str = dupprintf("No supported authentication methods available" | |
8638 | " (server sent: %.*s)", | |
8639 | methlen, methods); | |
8640 | ||
8641 | ssh_disconnect(ssh, str, | |
8642 | "No supported authentication methods available", | |
8643 | SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, | |
8644 | FALSE); | |
8645 | sfree(str); | |
8646 | ||
8647 | crStopV; | |
8648 | ||
8649 | } | |
8650 | ||
8651 | } | |
8652 | } | |
8653 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; | |
8654 | ||
8655 | /* Clear up various bits and pieces from authentication. */ | |
8656 | if (s->publickey_blob) { | |
8657 | sfree(s->publickey_blob); | |
8658 | sfree(s->publickey_comment); | |
8659 | } | |
8660 | if (s->agent_response) | |
8661 | sfree(s->agent_response); | |
8662 | ||
8663 | if (s->userauth_success) { | |
8664 | /* | |
8665 | * We've just received USERAUTH_SUCCESS, and we haven't sent any | |
8666 | * packets since. Signal the transport layer to consider enacting | |
8667 | * delayed compression. | |
8668 | * | |
8669 | * (Relying on we_are_in is not sufficient, as | |
8670 | * draft-miller-secsh-compression-delayed is quite clear that it | |
8671 | * triggers on USERAUTH_SUCCESS specifically, and we_are_in can | |
8672 | * become set for other reasons.) | |
8673 | */ | |
8674 | do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL); | |
8675 | } | |
8676 | ||
8677 | /* | |
8678 | * Now the connection protocol has started, one way or another. | |
8679 | */ | |
8680 | ||
8681 | ssh->channels = newtree234(ssh_channelcmp); | |
8682 | ||
8683 | /* | |
8684 | * Set up handlers for some connection protocol messages, so we | |
8685 | * don't have to handle them repeatedly in this coroutine. | |
8686 | */ | |
8687 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = | |
8688 | ssh2_msg_channel_window_adjust; | |
8689 | ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = | |
8690 | ssh2_msg_global_request; | |
8691 | ||
8692 | /* | |
8693 | * Create the main session channel. | |
8694 | */ | |
8695 | if (ssh->cfg.ssh_no_shell) { | |
8696 | ssh->mainchan = NULL; | |
8697 | } else if (*ssh->cfg.ssh_nc_host) { | |
8698 | /* | |
8699 | * Just start a direct-tcpip channel and use it as the main | |
8700 | * channel. | |
8701 | */ | |
8702 | ssh->mainchan = snew(struct ssh_channel); | |
8703 | ssh->mainchan->ssh = ssh; | |
8704 | ssh2_channel_init(ssh->mainchan); | |
8705 | logeventf(ssh, | |
8706 | "Opening direct-tcpip channel to %s:%d in place of session", | |
8707 | ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port); | |
8708 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); | |
8709 | ssh2_pkt_addstring(s->pktout, "direct-tcpip"); | |
8710 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); | |
8711 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ | |
8712 | ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ | |
8713 | ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host); | |
8714 | ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port); | |
8715 | /* | |
8716 | * There's nothing meaningful to put in the originator | |
8717 | * fields, but some servers insist on syntactically correct | |
8718 | * information. | |
8719 | */ | |
8720 | ssh2_pkt_addstring(s->pktout, "0.0.0.0"); | |
8721 | ssh2_pkt_adduint32(s->pktout, 0); | |
8722 | ssh2_pkt_send(ssh, s->pktout); | |
8723 | ||
8724 | crWaitUntilV(pktin); | |
8725 | if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { | |
8726 | bombout(("Server refused to open a direct-tcpip channel")); | |
8727 | crStopV; | |
8728 | /* FIXME: error data comes back in FAILURE packet */ | |
8729 | } | |
8730 | if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { | |
8731 | bombout(("Server's channel confirmation cited wrong channel")); | |
8732 | crStopV; | |
8733 | } | |
8734 | ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); | |
8735 | ssh->mainchan->halfopen = FALSE; | |
8736 | ssh->mainchan->type = CHAN_MAINSESSION; | |
8737 | ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); | |
8738 | ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); | |
8739 | add234(ssh->channels, ssh->mainchan); | |
8740 | update_specials_menu(ssh->frontend); | |
8741 | logevent("Opened direct-tcpip channel"); | |
8742 | ssh->ncmode = TRUE; | |
8743 | } else { | |
8744 | ssh->mainchan = snew(struct ssh_channel); | |
8745 | ssh->mainchan->ssh = ssh; | |
8746 | ssh2_channel_init(ssh->mainchan); | |
8747 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); | |
8748 | ssh2_pkt_addstring(s->pktout, "session"); | |
8749 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); | |
8750 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ | |
8751 | ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ | |
8752 | ssh2_pkt_send(ssh, s->pktout); | |
8753 | crWaitUntilV(pktin); | |
8754 | if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { | |
8755 | bombout(("Server refused to open a session")); | |
8756 | crStopV; | |
8757 | /* FIXME: error data comes back in FAILURE packet */ | |
8758 | } | |
8759 | if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { | |
8760 | bombout(("Server's channel confirmation cited wrong channel")); | |
8761 | crStopV; | |
8762 | } | |
8763 | ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); | |
8764 | ssh->mainchan->halfopen = FALSE; | |
8765 | ssh->mainchan->type = CHAN_MAINSESSION; | |
8766 | ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); | |
8767 | ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); | |
8768 | add234(ssh->channels, ssh->mainchan); | |
8769 | update_specials_menu(ssh->frontend); | |
8770 | logevent("Opened channel for session"); | |
8771 | ssh->ncmode = FALSE; | |
8772 | } | |
8773 | ||
8774 | /* | |
8775 | * Now we have a channel, make dispatch table entries for | |
8776 | * general channel-based messages. | |
8777 | */ | |
8778 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = | |
8779 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = | |
8780 | ssh2_msg_channel_data; | |
8781 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof; | |
8782 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close; | |
8783 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = | |
8784 | ssh2_msg_channel_open_confirmation; | |
8785 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = | |
8786 | ssh2_msg_channel_open_failure; | |
8787 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = | |
8788 | ssh2_msg_channel_request; | |
8789 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = | |
8790 | ssh2_msg_channel_open; | |
8791 | ||
8792 | if (ssh->mainchan && ssh->cfg.ssh_simple) { | |
8793 | /* | |
8794 | * This message indicates to the server that we promise | |
8795 | * not to try to run any other channel in parallel with | |
8796 | * this one, so it's safe for it to advertise a very large | |
8797 | * window and leave the flow control to TCP. | |
8798 | */ | |
8799 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
8800 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); | |
8801 | ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org"); | |
8802 | ssh2_pkt_addbool(s->pktout, 0); /* no reply */ | |
8803 | ssh2_pkt_send(ssh, s->pktout); | |
8804 | } | |
8805 | ||
8806 | /* | |
8807 | * Potentially enable X11 forwarding. | |
8808 | */ | |
8809 | if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward && | |
8810 | (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display, | |
8811 | ssh->cfg.x11_auth, &ssh->cfg))) { | |
8812 | logevent("Requesting X11 forwarding"); | |
8813 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
8814 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); | |
8815 | ssh2_pkt_addstring(s->pktout, "x11-req"); | |
8816 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
8817 | ssh2_pkt_addbool(s->pktout, 0); /* many connections */ | |
8818 | ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname); | |
8819 | /* | |
8820 | * Note that while we blank the X authentication data here, we don't | |
8821 | * take any special action to blank the start of an X11 channel, | |
8822 | * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection | |
8823 | * without having session blanking enabled is likely to leak your | |
8824 | * cookie into the log. | |
8825 | */ | |
8826 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); | |
8827 | ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring); | |
8828 | end_log_omission(ssh, s->pktout); | |
8829 | ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum); | |
8830 | ssh2_pkt_send(ssh, s->pktout); | |
8831 | ||
8832 | crWaitUntilV(pktin); | |
8833 | ||
8834 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { | |
8835 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { | |
8836 | bombout(("Unexpected response to X11 forwarding request:" | |
8837 | " packet type %d", pktin->type)); | |
8838 | crStopV; | |
8839 | } | |
8840 | logevent("X11 forwarding refused"); | |
8841 | } else { | |
8842 | logevent("X11 forwarding enabled"); | |
8843 | ssh->X11_fwd_enabled = TRUE; | |
8844 | } | |
8845 | } | |
8846 | ||
8847 | /* | |
8848 | * Enable port forwardings. | |
8849 | */ | |
8850 | ssh_setup_portfwd(ssh, &ssh->cfg); | |
8851 | ||
8852 | /* | |
8853 | * Potentially enable agent forwarding. | |
8854 | */ | |
8855 | if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) { | |
8856 | logevent("Requesting OpenSSH-style agent forwarding"); | |
8857 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
8858 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); | |
8859 | ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com"); | |
8860 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
8861 | ssh2_pkt_send(ssh, s->pktout); | |
8862 | ||
8863 | crWaitUntilV(pktin); | |
8864 | ||
8865 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { | |
8866 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { | |
8867 | bombout(("Unexpected response to agent forwarding request:" | |
8868 | " packet type %d", pktin->type)); | |
8869 | crStopV; | |
8870 | } | |
8871 | logevent("Agent forwarding refused"); | |
8872 | } else { | |
8873 | logevent("Agent forwarding enabled"); | |
8874 | ssh->agentfwd_enabled = TRUE; | |
8875 | } | |
8876 | } | |
8877 | ||
8878 | /* | |
8879 | * Now allocate a pty for the session. | |
8880 | */ | |
8881 | if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) { | |
8882 | /* Unpick the terminal-speed string. */ | |
8883 | /* XXX perhaps we should allow no speeds to be sent. */ | |
8884 | ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ | |
8885 | sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed); | |
8886 | /* Build the pty request. */ | |
8887 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
8888 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */ | |
8889 | ssh2_pkt_addstring(s->pktout, "pty-req"); | |
8890 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
8891 | ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype); | |
8892 | ssh2_pkt_adduint32(s->pktout, ssh->term_width); | |
8893 | ssh2_pkt_adduint32(s->pktout, ssh->term_height); | |
8894 | ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */ | |
8895 | ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */ | |
8896 | ssh2_pkt_addstring_start(s->pktout); | |
8897 | parse_ttymodes(ssh, ssh->cfg.ttymodes, | |
8898 | ssh2_send_ttymode, (void *)s->pktout); | |
8899 | ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED); | |
8900 | ssh2_pkt_adduint32(s->pktout, ssh->ispeed); | |
8901 | ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED); | |
8902 | ssh2_pkt_adduint32(s->pktout, ssh->ospeed); | |
8903 | ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */ | |
8904 | ssh2_pkt_send(ssh, s->pktout); | |
8905 | ssh->state = SSH_STATE_INTERMED; | |
8906 | ||
8907 | crWaitUntilV(pktin); | |
8908 | ||
8909 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { | |
8910 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { | |
8911 | bombout(("Unexpected response to pty request:" | |
8912 | " packet type %d", pktin->type)); | |
8913 | crStopV; | |
8914 | } | |
8915 | c_write_str(ssh, "Server refused to allocate pty\r\n"); | |
8916 | ssh->editing = ssh->echoing = 1; | |
8917 | } else { | |
8918 | logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", | |
8919 | ssh->ospeed, ssh->ispeed); | |
8920 | } | |
8921 | } else { | |
8922 | ssh->editing = ssh->echoing = 1; | |
8923 | } | |
8924 | ||
8925 | /* | |
8926 | * Send environment variables. | |
8927 | * | |
8928 | * Simplest thing here is to send all the requests at once, and | |
8929 | * then wait for a whole bunch of successes or failures. | |
8930 | */ | |
8931 | if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) { | |
8932 | char *e = ssh->cfg.environmt; | |
8933 | char *var, *varend, *val; | |
8934 | ||
8935 | s->num_env = 0; | |
8936 | ||
8937 | while (*e) { | |
8938 | var = e; | |
8939 | while (*e && *e != '\t') e++; | |
8940 | varend = e; | |
8941 | if (*e == '\t') e++; | |
8942 | val = e; | |
8943 | while (*e) e++; | |
8944 | e++; | |
8945 | ||
8946 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
8947 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); | |
8948 | ssh2_pkt_addstring(s->pktout, "env"); | |
8949 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
8950 | ssh2_pkt_addstring_start(s->pktout); | |
8951 | ssh2_pkt_addstring_data(s->pktout, var, varend-var); | |
8952 | ssh2_pkt_addstring(s->pktout, val); | |
8953 | ssh2_pkt_send(ssh, s->pktout); | |
8954 | ||
8955 | s->num_env++; | |
8956 | } | |
8957 | ||
8958 | logeventf(ssh, "Sent %d environment variables", s->num_env); | |
8959 | ||
8960 | s->env_ok = 0; | |
8961 | s->env_left = s->num_env; | |
8962 | ||
8963 | while (s->env_left > 0) { | |
8964 | crWaitUntilV(pktin); | |
8965 | ||
8966 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { | |
8967 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { | |
8968 | bombout(("Unexpected response to environment request:" | |
8969 | " packet type %d", pktin->type)); | |
8970 | crStopV; | |
8971 | } | |
8972 | } else { | |
8973 | s->env_ok++; | |
8974 | } | |
8975 | ||
8976 | s->env_left--; | |
8977 | } | |
8978 | ||
8979 | if (s->env_ok == s->num_env) { | |
8980 | logevent("All environment variables successfully set"); | |
8981 | } else if (s->env_ok == 0) { | |
8982 | logevent("All environment variables refused"); | |
8983 | c_write_str(ssh, "Server refused to set environment variables\r\n"); | |
8984 | } else { | |
8985 | logeventf(ssh, "%d environment variables refused", | |
8986 | s->num_env - s->env_ok); | |
8987 | c_write_str(ssh, "Server refused to set all environment variables\r\n"); | |
8988 | } | |
8989 | } | |
8990 | ||
8991 | /* | |
8992 | * Start a shell or a remote command. We may have to attempt | |
8993 | * this twice if the config data has provided a second choice | |
8994 | * of command. | |
8995 | */ | |
8996 | if (ssh->mainchan && !ssh->ncmode) while (1) { | |
8997 | int subsys; | |
8998 | char *cmd; | |
8999 | ||
9000 | if (ssh->fallback_cmd) { | |
9001 | subsys = ssh->cfg.ssh_subsys2; | |
9002 | cmd = ssh->cfg.remote_cmd_ptr2; | |
9003 | } else { | |
9004 | subsys = ssh->cfg.ssh_subsys; | |
9005 | cmd = ssh->cfg.remote_cmd_ptr; | |
9006 | if (!cmd) cmd = ssh->cfg.remote_cmd; | |
9007 | } | |
9008 | ||
9009 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
9010 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */ | |
9011 | if (subsys) { | |
9012 | ssh2_pkt_addstring(s->pktout, "subsystem"); | |
9013 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
9014 | ssh2_pkt_addstring(s->pktout, cmd); | |
9015 | } else if (*cmd) { | |
9016 | ssh2_pkt_addstring(s->pktout, "exec"); | |
9017 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
9018 | ssh2_pkt_addstring(s->pktout, cmd); | |
9019 | } else { | |
9020 | ssh2_pkt_addstring(s->pktout, "shell"); | |
9021 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ | |
9022 | } | |
9023 | ssh2_pkt_send(ssh, s->pktout); | |
9024 | ||
9025 | crWaitUntilV(pktin); | |
9026 | ||
9027 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { | |
9028 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { | |
9029 | bombout(("Unexpected response to shell/command request:" | |
9030 | " packet type %d", pktin->type)); | |
9031 | crStopV; | |
9032 | } | |
9033 | /* | |
9034 | * We failed to start the command. If this is the | |
9035 | * fallback command, we really are finished; if it's | |
9036 | * not, and if the fallback command exists, try falling | |
9037 | * back to it before complaining. | |
9038 | */ | |
9039 | if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) { | |
9040 | logevent("Primary command failed; attempting fallback"); | |
9041 | ssh->fallback_cmd = TRUE; | |
9042 | continue; | |
9043 | } | |
9044 | bombout(("Server refused to start a shell/command")); | |
9045 | crStopV; | |
9046 | } else { | |
9047 | logevent("Started a shell/command"); | |
9048 | } | |
9049 | break; | |
9050 | } | |
9051 | ||
9052 | ssh->state = SSH_STATE_SESSION; | |
9053 | if (ssh->size_needed) | |
9054 | ssh_size(ssh, ssh->term_width, ssh->term_height); | |
9055 | if (ssh->eof_needed) | |
9056 | ssh_special(ssh, TS_EOF); | |
9057 | ||
9058 | /* | |
9059 | * All the initial channel requests are done, so install the default | |
9060 | * failure handler. | |
9061 | */ | |
9062 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success; | |
9063 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure; | |
9064 | ||
9065 | /* | |
9066 | * Transfer data! | |
9067 | */ | |
9068 | if (ssh->ldisc) | |
9069 | ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ | |
9070 | if (ssh->mainchan) | |
9071 | ssh->send_ok = 1; | |
9072 | while (1) { | |
9073 | crReturnV; | |
9074 | s->try_send = FALSE; | |
9075 | if (pktin) { | |
9076 | ||
9077 | /* | |
9078 | * _All_ the connection-layer packets we expect to | |
9079 | * receive are now handled by the dispatch table. | |
9080 | * Anything that reaches here must be bogus. | |
9081 | */ | |
9082 | ||
9083 | bombout(("Strange packet received: type %d", pktin->type)); | |
9084 | crStopV; | |
9085 | } else if (ssh->mainchan) { | |
9086 | /* | |
9087 | * We have spare data. Add it to the channel buffer. | |
9088 | */ | |
9089 | ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen); | |
9090 | s->try_send = TRUE; | |
9091 | } | |
9092 | if (s->try_send) { | |
9093 | int i; | |
9094 | struct ssh_channel *c; | |
9095 | /* | |
9096 | * Try to send data on all channels if we can. | |
9097 | */ | |
9098 | for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) | |
9099 | ssh2_try_send_and_unthrottle(ssh, c); | |
9100 | } | |
9101 | } | |
9102 | ||
9103 | crFinishV; | |
9104 | } | |
9105 | ||
9106 | /* | |
9107 | * Handlers for SSH-2 messages that might arrive at any moment. | |
9108 | */ | |
9109 | static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) | |
9110 | { | |
9111 | /* log reason code in disconnect message */ | |
9112 | char *buf, *msg; | |
9113 | int reason, msglen; | |
9114 | ||
9115 | reason = ssh_pkt_getuint32(pktin); | |
9116 | ssh_pkt_getstring(pktin, &msg, &msglen); | |
9117 | ||
9118 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { | |
9119 | buf = dupprintf("Received disconnect message (%s)", | |
9120 | ssh2_disconnect_reasons[reason]); | |
9121 | } else { | |
9122 | buf = dupprintf("Received disconnect message (unknown" | |
9123 | " type %d)", reason); | |
9124 | } | |
9125 | logevent(buf); | |
9126 | sfree(buf); | |
9127 | buf = dupprintf("Disconnection message text: %.*s", | |
9128 | msglen, msg); | |
9129 | logevent(buf); | |
9130 | bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"", | |
9131 | reason, | |
9132 | (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? | |
9133 | ssh2_disconnect_reasons[reason] : "unknown", | |
9134 | msglen, msg)); | |
9135 | sfree(buf); | |
9136 | } | |
9137 | ||
9138 | static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) | |
9139 | { | |
9140 | /* log the debug message */ | |
9141 | char *msg; | |
9142 | int msglen; | |
9143 | ||
9144 | /* XXX maybe we should actually take notice of the return value */ | |
9145 | ssh2_pkt_getbool(pktin); | |
9146 | ssh_pkt_getstring(pktin, &msg, &msglen); | |
9147 | ||
9148 | logeventf(ssh, "Remote debug message: %.*s", msglen, msg); | |
9149 | } | |
9150 | ||
9151 | static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) | |
9152 | { | |
9153 | struct Packet *pktout; | |
9154 | pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); | |
9155 | ssh2_pkt_adduint32(pktout, pktin->sequence); | |
9156 | /* | |
9157 | * UNIMPLEMENTED messages MUST appear in the same order as the | |
9158 | * messages they respond to. Hence, never queue them. | |
9159 | */ | |
9160 | ssh2_pkt_send_noqueue(ssh, pktout); | |
9161 | } | |
9162 | ||
9163 | /* | |
9164 | * Handle the top-level SSH-2 protocol. | |
9165 | */ | |
9166 | static void ssh2_protocol_setup(Ssh ssh) | |
9167 | { | |
9168 | int i; | |
9169 | ||
9170 | /* | |
9171 | * Most messages cause SSH2_MSG_UNIMPLEMENTED. | |
9172 | */ | |
9173 | for (i = 0; i < 256; i++) | |
9174 | ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented; | |
9175 | ||
9176 | /* | |
9177 | * Any message we actually understand, we set to NULL so that | |
9178 | * the coroutines will get it. | |
9179 | */ | |
9180 | ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL; | |
9181 | ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL; | |
9182 | ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL; | |
9183 | ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL; | |
9184 | ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL; | |
9185 | ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL; | |
9186 | ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL; | |
9187 | /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */ | |
9188 | /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */ | |
9189 | ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL; | |
9190 | ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL; | |
9191 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL; | |
9192 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL; | |
9193 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL; | |
9194 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; | |
9195 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL; | |
9196 | /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */ | |
9197 | /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */ | |
9198 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL; | |
9199 | ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL; | |
9200 | ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL; | |
9201 | ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL; | |
9202 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL; | |
9203 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL; | |
9204 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL; | |
9205 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL; | |
9206 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL; | |
9207 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL; | |
9208 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL; | |
9209 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL; | |
9210 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL; | |
9211 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL; | |
9212 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL; | |
9213 | ||
9214 | /* | |
9215 | * These special message types we install handlers for. | |
9216 | */ | |
9217 | ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; | |
9218 | ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */ | |
9219 | ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; | |
9220 | } | |
9221 | ||
9222 | static void ssh2_timer(void *ctx, long now) | |
9223 | { | |
9224 | Ssh ssh = (Ssh)ctx; | |
9225 | ||
9226 | if (ssh->state == SSH_STATE_CLOSED) | |
9227 | return; | |
9228 | ||
9229 | if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 && | |
9230 | now - ssh->next_rekey >= 0) { | |
9231 | do_ssh2_transport(ssh, "timeout", -1, NULL); | |
9232 | } | |
9233 | } | |
9234 | ||
9235 | static void ssh2_protocol(Ssh ssh, void *vin, int inlen, | |
9236 | struct Packet *pktin) | |
9237 | { | |
9238 | unsigned char *in = (unsigned char *)vin; | |
9239 | if (ssh->state == SSH_STATE_CLOSED) | |
9240 | return; | |
9241 | ||
9242 | if (pktin) { | |
9243 | ssh->incoming_data_size += pktin->encrypted_len; | |
9244 | if (!ssh->kex_in_progress && | |
9245 | ssh->max_data_size != 0 && | |
9246 | ssh->incoming_data_size > ssh->max_data_size) | |
9247 | do_ssh2_transport(ssh, "too much data received", -1, NULL); | |
9248 | } | |
9249 | ||
9250 | if (pktin && ssh->packet_dispatch[pktin->type]) { | |
9251 | ssh->packet_dispatch[pktin->type](ssh, pktin); | |
9252 | return; | |
9253 | } | |
9254 | ||
9255 | if (!ssh->protocol_initial_phase_done || | |
9256 | (pktin && pktin->type >= 20 && pktin->type < 50)) { | |
9257 | if (do_ssh2_transport(ssh, in, inlen, pktin) && | |
9258 | !ssh->protocol_initial_phase_done) { | |
9259 | ssh->protocol_initial_phase_done = TRUE; | |
9260 | /* | |
9261 | * Allow authconn to initialise itself. | |
9262 | */ | |
9263 | do_ssh2_authconn(ssh, NULL, 0, NULL); | |
9264 | } | |
9265 | } else { | |
9266 | do_ssh2_authconn(ssh, in, inlen, pktin); | |
9267 | } | |
9268 | } | |
9269 | ||
9270 | /* | |
9271 | * Called to set up the connection. | |
9272 | * | |
9273 | * Returns an error message, or NULL on success. | |
9274 | */ | |
9275 | static const char *ssh_init(void *frontend_handle, void **backend_handle, | |
9276 | Config *cfg, | |
9277 | char *host, int port, char **realhost, int nodelay, | |
9278 | int keepalive) | |
9279 | { | |
9280 | const char *p; | |
9281 | Ssh ssh; | |
9282 | ||
9283 | ssh = snew(struct ssh_tag); | |
9284 | ssh->cfg = *cfg; /* STRUCTURE COPY */ | |
9285 | ssh->version = 0; /* when not ready yet */ | |
9286 | ssh->s = NULL; | |
9287 | ssh->cipher = NULL; | |
9288 | ssh->v1_cipher_ctx = NULL; | |
9289 | ssh->crcda_ctx = NULL; | |
9290 | ssh->cscipher = NULL; | |
9291 | ssh->cs_cipher_ctx = NULL; | |
9292 | ssh->sccipher = NULL; | |
9293 | ssh->sc_cipher_ctx = NULL; | |
9294 | ssh->csmac = NULL; | |
9295 | ssh->cs_mac_ctx = NULL; | |
9296 | ssh->scmac = NULL; | |
9297 | ssh->sc_mac_ctx = NULL; | |
9298 | ssh->cscomp = NULL; | |
9299 | ssh->cs_comp_ctx = NULL; | |
9300 | ssh->sccomp = NULL; | |
9301 | ssh->sc_comp_ctx = NULL; | |
9302 | ssh->kex = NULL; | |
9303 | ssh->kex_ctx = NULL; | |
9304 | ssh->hostkey = NULL; | |
9305 | ssh->exitcode = -1; | |
9306 | ssh->close_expected = FALSE; | |
9307 | ssh->clean_exit = FALSE; | |
9308 | ssh->state = SSH_STATE_PREPACKET; | |
9309 | ssh->size_needed = FALSE; | |
9310 | ssh->eof_needed = FALSE; | |
9311 | ssh->ldisc = NULL; | |
9312 | ssh->logctx = NULL; | |
9313 | ssh->deferred_send_data = NULL; | |
9314 | ssh->deferred_len = 0; | |
9315 | ssh->deferred_size = 0; | |
9316 | ssh->fallback_cmd = 0; | |
9317 | ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; | |
9318 | ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; | |
9319 | ssh->x11disp = NULL; | |
9320 | ssh->v1_compressing = FALSE; | |
9321 | ssh->v2_outgoing_sequence = 0; | |
9322 | ssh->ssh1_rdpkt_crstate = 0; | |
9323 | ssh->ssh2_rdpkt_crstate = 0; | |
9324 | ssh->do_ssh_init_crstate = 0; | |
9325 | ssh->ssh_gotdata_crstate = 0; | |
9326 | ssh->do_ssh1_connection_crstate = 0; | |
9327 | ssh->do_ssh1_login_crstate = 0; | |
9328 | ssh->do_ssh2_transport_crstate = 0; | |
9329 | ssh->do_ssh2_authconn_crstate = 0; | |
9330 | ssh->do_ssh_init_state = NULL; | |
9331 | ssh->do_ssh1_login_state = NULL; | |
9332 | ssh->do_ssh2_transport_state = NULL; | |
9333 | ssh->do_ssh2_authconn_state = NULL; | |
9334 | ssh->v_c = NULL; | |
9335 | ssh->v_s = NULL; | |
9336 | ssh->mainchan = NULL; | |
9337 | ssh->throttled_all = 0; | |
9338 | ssh->v1_stdout_throttling = 0; | |
9339 | ssh->queue = NULL; | |
9340 | ssh->queuelen = ssh->queuesize = 0; | |
9341 | ssh->queueing = FALSE; | |
9342 | ssh->qhead = ssh->qtail = NULL; | |
9343 | ssh->deferred_rekey_reason = NULL; | |
9344 | bufchain_init(&ssh->queued_incoming_data); | |
9345 | ssh->frozen = FALSE; | |
9346 | ||
9347 | *backend_handle = ssh; | |
9348 | ||
9349 | #ifdef MSCRYPTOAPI | |
9350 | if (crypto_startup() == 0) | |
9351 | return "Microsoft high encryption pack not installed!"; | |
9352 | #endif | |
9353 | ||
9354 | ssh->frontend = frontend_handle; | |
9355 | ssh->term_width = ssh->cfg.width; | |
9356 | ssh->term_height = ssh->cfg.height; | |
9357 | ||
9358 | ssh->channels = NULL; | |
9359 | ssh->rportfwds = NULL; | |
9360 | ssh->portfwds = NULL; | |
9361 | ||
9362 | ssh->send_ok = 0; | |
9363 | ssh->editing = 0; | |
9364 | ssh->echoing = 0; | |
9365 | ssh->conn_throttle_count = 0; | |
9366 | ssh->overall_bufsize = 0; | |
9367 | ssh->fallback_cmd = 0; | |
9368 | ||
9369 | ssh->protocol = NULL; | |
9370 | ||
9371 | ssh->protocol_initial_phase_done = FALSE; | |
9372 | ||
9373 | ssh->pinger = NULL; | |
9374 | ||
9375 | ssh->incoming_data_size = ssh->outgoing_data_size = | |
9376 | ssh->deferred_data_size = 0L; | |
9377 | ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data); | |
9378 | ssh->kex_in_progress = FALSE; | |
9379 | ||
9380 | #ifndef NO_GSSAPI | |
9381 | ssh->gsslibs = NULL; | |
9382 | #endif | |
9383 | ||
9384 | p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); | |
9385 | if (p != NULL) | |
9386 | return p; | |
9387 | ||
9388 | random_ref(); | |
9389 | ||
9390 | return NULL; | |
9391 | } | |
9392 | ||
9393 | static void ssh_free(void *handle) | |
9394 | { | |
9395 | Ssh ssh = (Ssh) handle; | |
9396 | struct ssh_channel *c; | |
9397 | struct ssh_rportfwd *pf; | |
9398 | ||
9399 | if (ssh->v1_cipher_ctx) | |
9400 | ssh->cipher->free_context(ssh->v1_cipher_ctx); | |
9401 | if (ssh->cs_cipher_ctx) | |
9402 | ssh->cscipher->free_context(ssh->cs_cipher_ctx); | |
9403 | if (ssh->sc_cipher_ctx) | |
9404 | ssh->sccipher->free_context(ssh->sc_cipher_ctx); | |
9405 | if (ssh->cs_mac_ctx) | |
9406 | ssh->csmac->free_context(ssh->cs_mac_ctx); | |
9407 | if (ssh->sc_mac_ctx) | |
9408 | ssh->scmac->free_context(ssh->sc_mac_ctx); | |
9409 | if (ssh->cs_comp_ctx) { | |
9410 | if (ssh->cscomp) | |
9411 | ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); | |
9412 | else | |
9413 | zlib_compress_cleanup(ssh->cs_comp_ctx); | |
9414 | } | |
9415 | if (ssh->sc_comp_ctx) { | |
9416 | if (ssh->sccomp) | |
9417 | ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); | |
9418 | else | |
9419 | zlib_decompress_cleanup(ssh->sc_comp_ctx); | |
9420 | } | |
9421 | if (ssh->kex_ctx) | |
9422 | dh_cleanup(ssh->kex_ctx); | |
9423 | sfree(ssh->savedhost); | |
9424 | ||
9425 | while (ssh->queuelen-- > 0) | |
9426 | ssh_free_packet(ssh->queue[ssh->queuelen]); | |
9427 | sfree(ssh->queue); | |
9428 | ||
9429 | while (ssh->qhead) { | |
9430 | struct queued_handler *qh = ssh->qhead; | |
9431 | ssh->qhead = qh->next; | |
9432 | sfree(ssh->qhead); | |
9433 | } | |
9434 | ssh->qhead = ssh->qtail = NULL; | |
9435 | ||
9436 | if (ssh->channels) { | |
9437 | while ((c = delpos234(ssh->channels, 0)) != NULL) { | |
9438 | switch (c->type) { | |
9439 | case CHAN_X11: | |
9440 | if (c->u.x11.s != NULL) | |
9441 | x11_close(c->u.x11.s); | |
9442 | break; | |
9443 | case CHAN_SOCKDATA: | |
9444 | case CHAN_SOCKDATA_DORMANT: | |
9445 | if (c->u.pfd.s != NULL) | |
9446 | pfd_close(c->u.pfd.s); | |
9447 | break; | |
9448 | } | |
9449 | sfree(c); | |
9450 | } | |
9451 | freetree234(ssh->channels); | |
9452 | ssh->channels = NULL; | |
9453 | } | |
9454 | ||
9455 | if (ssh->rportfwds) { | |
9456 | while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) | |
9457 | free_rportfwd(pf); | |
9458 | freetree234(ssh->rportfwds); | |
9459 | ssh->rportfwds = NULL; | |
9460 | } | |
9461 | sfree(ssh->deferred_send_data); | |
9462 | if (ssh->x11disp) | |
9463 | x11_free_display(ssh->x11disp); | |
9464 | sfree(ssh->do_ssh_init_state); | |
9465 | sfree(ssh->do_ssh1_login_state); | |
9466 | sfree(ssh->do_ssh2_transport_state); | |
9467 | sfree(ssh->do_ssh2_authconn_state); | |
9468 | sfree(ssh->v_c); | |
9469 | sfree(ssh->v_s); | |
9470 | sfree(ssh->fullhostname); | |
9471 | if (ssh->crcda_ctx) { | |
9472 | crcda_free_context(ssh->crcda_ctx); | |
9473 | ssh->crcda_ctx = NULL; | |
9474 | } | |
9475 | if (ssh->s) | |
9476 | ssh_do_close(ssh, TRUE); | |
9477 | expire_timer_context(ssh); | |
9478 | if (ssh->pinger) | |
9479 | pinger_free(ssh->pinger); | |
9480 | bufchain_clear(&ssh->queued_incoming_data); | |
9481 | #ifndef NO_GSSAPI | |
9482 | if (ssh->gsslibs) | |
9483 | ssh_gss_cleanup(ssh->gsslibs); | |
9484 | #endif | |
9485 | sfree(ssh); | |
9486 | ||
9487 | random_unref(); | |
9488 | } | |
9489 | ||
9490 | /* | |
9491 | * Reconfigure the SSH backend. | |
9492 | */ | |
9493 | static void ssh_reconfig(void *handle, Config *cfg) | |
9494 | { | |
9495 | Ssh ssh = (Ssh) handle; | |
9496 | char *rekeying = NULL, rekey_mandatory = FALSE; | |
9497 | unsigned long old_max_data_size; | |
9498 | ||
9499 | pinger_reconfig(ssh->pinger, &ssh->cfg, cfg); | |
9500 | if (ssh->portfwds) | |
9501 | ssh_setup_portfwd(ssh, cfg); | |
9502 | ||
9503 | if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time && | |
9504 | cfg->ssh_rekey_time != 0) { | |
9505 | long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC; | |
9506 | long now = GETTICKCOUNT(); | |
9507 | ||
9508 | if (new_next - now < 0) { | |
9509 | rekeying = "timeout shortened"; | |
9510 | } else { | |
9511 | ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh); | |
9512 | } | |
9513 | } | |
9514 | ||
9515 | old_max_data_size = ssh->max_data_size; | |
9516 | ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data); | |
9517 | if (old_max_data_size != ssh->max_data_size && | |
9518 | ssh->max_data_size != 0) { | |
9519 | if (ssh->outgoing_data_size > ssh->max_data_size || | |
9520 | ssh->incoming_data_size > ssh->max_data_size) | |
9521 | rekeying = "data limit lowered"; | |
9522 | } | |
9523 | ||
9524 | if (ssh->cfg.compression != cfg->compression) { | |
9525 | rekeying = "compression setting changed"; | |
9526 | rekey_mandatory = TRUE; | |
9527 | } | |
9528 | ||
9529 | if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc || | |
9530 | memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist, | |
9531 | sizeof(ssh->cfg.ssh_cipherlist))) { | |
9532 | rekeying = "cipher settings changed"; | |
9533 | rekey_mandatory = TRUE; | |
9534 | } | |
9535 | ||
9536 | ssh->cfg = *cfg; /* STRUCTURE COPY */ | |
9537 | ||
9538 | if (rekeying) { | |
9539 | if (!ssh->kex_in_progress) { | |
9540 | do_ssh2_transport(ssh, rekeying, -1, NULL); | |
9541 | } else if (rekey_mandatory) { | |
9542 | ssh->deferred_rekey_reason = rekeying; | |
9543 | } | |
9544 | } | |
9545 | } | |
9546 | ||
9547 | /* | |
9548 | * Called to send data down the SSH connection. | |
9549 | */ | |
9550 | static int ssh_send(void *handle, char *buf, int len) | |
9551 | { | |
9552 | Ssh ssh = (Ssh) handle; | |
9553 | ||
9554 | if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) | |
9555 | return 0; | |
9556 | ||
9557 | ssh->protocol(ssh, (unsigned char *)buf, len, 0); | |
9558 | ||
9559 | return ssh_sendbuffer(ssh); | |
9560 | } | |
9561 | ||
9562 | /* | |
9563 | * Called to query the current amount of buffered stdin data. | |
9564 | */ | |
9565 | static int ssh_sendbuffer(void *handle) | |
9566 | { | |
9567 | Ssh ssh = (Ssh) handle; | |
9568 | int override_value; | |
9569 | ||
9570 | if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) | |
9571 | return 0; | |
9572 | ||
9573 | /* | |
9574 | * If the SSH socket itself has backed up, add the total backup | |
9575 | * size on that to any individual buffer on the stdin channel. | |
9576 | */ | |
9577 | override_value = 0; | |
9578 | if (ssh->throttled_all) | |
9579 | override_value = ssh->overall_bufsize; | |
9580 | ||
9581 | if (ssh->version == 1) { | |
9582 | return override_value; | |
9583 | } else if (ssh->version == 2) { | |
9584 | if (!ssh->mainchan || ssh->mainchan->closes > 0) | |
9585 | return override_value; | |
9586 | else | |
9587 | return (override_value + | |
9588 | bufchain_size(&ssh->mainchan->v.v2.outbuffer)); | |
9589 | } | |
9590 | ||
9591 | return 0; | |
9592 | } | |
9593 | ||
9594 | /* | |
9595 | * Called to set the size of the window from SSH's POV. | |
9596 | */ | |
9597 | static void ssh_size(void *handle, int width, int height) | |
9598 | { | |
9599 | Ssh ssh = (Ssh) handle; | |
9600 | struct Packet *pktout; | |
9601 | ||
9602 | ssh->term_width = width; | |
9603 | ssh->term_height = height; | |
9604 | ||
9605 | switch (ssh->state) { | |
9606 | case SSH_STATE_BEFORE_SIZE: | |
9607 | case SSH_STATE_PREPACKET: | |
9608 | case SSH_STATE_CLOSED: | |
9609 | break; /* do nothing */ | |
9610 | case SSH_STATE_INTERMED: | |
9611 | ssh->size_needed = TRUE; /* buffer for later */ | |
9612 | break; | |
9613 | case SSH_STATE_SESSION: | |
9614 | if (!ssh->cfg.nopty) { | |
9615 | if (ssh->version == 1) { | |
9616 | send_packet(ssh, SSH1_CMSG_WINDOW_SIZE, | |
9617 | PKT_INT, ssh->term_height, | |
9618 | PKT_INT, ssh->term_width, | |
9619 | PKT_INT, 0, PKT_INT, 0, PKT_END); | |
9620 | } else if (ssh->mainchan) { | |
9621 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
9622 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); | |
9623 | ssh2_pkt_addstring(pktout, "window-change"); | |
9624 | ssh2_pkt_addbool(pktout, 0); | |
9625 | ssh2_pkt_adduint32(pktout, ssh->term_width); | |
9626 | ssh2_pkt_adduint32(pktout, ssh->term_height); | |
9627 | ssh2_pkt_adduint32(pktout, 0); | |
9628 | ssh2_pkt_adduint32(pktout, 0); | |
9629 | ssh2_pkt_send(ssh, pktout); | |
9630 | } | |
9631 | } | |
9632 | break; | |
9633 | } | |
9634 | } | |
9635 | ||
9636 | /* | |
9637 | * Return a list of the special codes that make sense in this | |
9638 | * protocol. | |
9639 | */ | |
9640 | static const struct telnet_special *ssh_get_specials(void *handle) | |
9641 | { | |
9642 | static const struct telnet_special ssh1_ignore_special[] = { | |
9643 | {"IGNORE message", TS_NOP} | |
9644 | }; | |
9645 | static const struct telnet_special ssh2_ignore_special[] = { | |
9646 | {"IGNORE message", TS_NOP}, | |
9647 | }; | |
9648 | static const struct telnet_special ssh2_rekey_special[] = { | |
9649 | {"Repeat key exchange", TS_REKEY}, | |
9650 | }; | |
9651 | static const struct telnet_special ssh2_session_specials[] = { | |
9652 | {NULL, TS_SEP}, | |
9653 | {"Break", TS_BRK}, | |
9654 | /* These are the signal names defined by RFC 4254. | |
9655 | * They include all the ISO C signals, but are a subset of the POSIX | |
9656 | * required signals. */ | |
9657 | {"SIGINT (Interrupt)", TS_SIGINT}, | |
9658 | {"SIGTERM (Terminate)", TS_SIGTERM}, | |
9659 | {"SIGKILL (Kill)", TS_SIGKILL}, | |
9660 | {"SIGQUIT (Quit)", TS_SIGQUIT}, | |
9661 | {"SIGHUP (Hangup)", TS_SIGHUP}, | |
9662 | {"More signals", TS_SUBMENU}, | |
9663 | {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM}, | |
9664 | {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL}, | |
9665 | {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV}, | |
9666 | {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2}, | |
9667 | {NULL, TS_EXITMENU} | |
9668 | }; | |
9669 | static const struct telnet_special specials_end[] = { | |
9670 | {NULL, TS_EXITMENU} | |
9671 | }; | |
9672 | /* XXX review this length for any changes: */ | |
9673 | static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) + | |
9674 | lenof(ssh2_rekey_special) + | |
9675 | lenof(ssh2_session_specials) + | |
9676 | lenof(specials_end)]; | |
9677 | Ssh ssh = (Ssh) handle; | |
9678 | int i = 0; | |
9679 | #define ADD_SPECIALS(name) \ | |
9680 | do { \ | |
9681 | assert((i + lenof(name)) <= lenof(ssh_specials)); \ | |
9682 | memcpy(&ssh_specials[i], name, sizeof name); \ | |
9683 | i += lenof(name); \ | |
9684 | } while(0) | |
9685 | ||
9686 | if (ssh->version == 1) { | |
9687 | /* Don't bother offering IGNORE if we've decided the remote | |
9688 | * won't cope with it, since we wouldn't bother sending it if | |
9689 | * asked anyway. */ | |
9690 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) | |
9691 | ADD_SPECIALS(ssh1_ignore_special); | |
9692 | } else if (ssh->version == 2) { | |
9693 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) | |
9694 | ADD_SPECIALS(ssh2_ignore_special); | |
9695 | if (!(ssh->remote_bugs & BUG_SSH2_REKEY)) | |
9696 | ADD_SPECIALS(ssh2_rekey_special); | |
9697 | if (ssh->mainchan) | |
9698 | ADD_SPECIALS(ssh2_session_specials); | |
9699 | } /* else we're not ready yet */ | |
9700 | ||
9701 | if (i) { | |
9702 | ADD_SPECIALS(specials_end); | |
9703 | return ssh_specials; | |
9704 | } else { | |
9705 | return NULL; | |
9706 | } | |
9707 | #undef ADD_SPECIALS | |
9708 | } | |
9709 | ||
9710 | /* | |
9711 | * Send special codes. TS_EOF is useful for `plink', so you | |
9712 | * can send an EOF and collect resulting output (e.g. `plink | |
9713 | * hostname sort'). | |
9714 | */ | |
9715 | static void ssh_special(void *handle, Telnet_Special code) | |
9716 | { | |
9717 | Ssh ssh = (Ssh) handle; | |
9718 | struct Packet *pktout; | |
9719 | ||
9720 | if (code == TS_EOF) { | |
9721 | if (ssh->state != SSH_STATE_SESSION) { | |
9722 | /* | |
9723 | * Buffer the EOF in case we are pre-SESSION, so we can | |
9724 | * send it as soon as we reach SESSION. | |
9725 | */ | |
9726 | if (code == TS_EOF) | |
9727 | ssh->eof_needed = TRUE; | |
9728 | return; | |
9729 | } | |
9730 | if (ssh->version == 1) { | |
9731 | send_packet(ssh, SSH1_CMSG_EOF, PKT_END); | |
9732 | } else if (ssh->mainchan) { | |
9733 | struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); | |
9734 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); | |
9735 | ssh2_pkt_send(ssh, pktout); | |
9736 | ssh->send_ok = 0; /* now stop trying to read from stdin */ | |
9737 | } | |
9738 | logevent("Sent EOF message"); | |
9739 | } else if (code == TS_PING || code == TS_NOP) { | |
9740 | if (ssh->state == SSH_STATE_CLOSED | |
9741 | || ssh->state == SSH_STATE_PREPACKET) return; | |
9742 | if (ssh->version == 1) { | |
9743 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) | |
9744 | send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); | |
9745 | } else { | |
9746 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { | |
9747 | pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); | |
9748 | ssh2_pkt_addstring_start(pktout); | |
9749 | ssh2_pkt_send_noqueue(ssh, pktout); | |
9750 | } | |
9751 | } | |
9752 | } else if (code == TS_REKEY) { | |
9753 | if (!ssh->kex_in_progress && ssh->version == 2) { | |
9754 | do_ssh2_transport(ssh, "at user request", -1, NULL); | |
9755 | } | |
9756 | } else if (code == TS_BRK) { | |
9757 | if (ssh->state == SSH_STATE_CLOSED | |
9758 | || ssh->state == SSH_STATE_PREPACKET) return; | |
9759 | if (ssh->version == 1) { | |
9760 | logevent("Unable to send BREAK signal in SSH-1"); | |
9761 | } else if (ssh->mainchan) { | |
9762 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
9763 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); | |
9764 | ssh2_pkt_addstring(pktout, "break"); | |
9765 | ssh2_pkt_addbool(pktout, 0); | |
9766 | ssh2_pkt_adduint32(pktout, 0); /* default break length */ | |
9767 | ssh2_pkt_send(ssh, pktout); | |
9768 | } | |
9769 | } else { | |
9770 | /* Is is a POSIX signal? */ | |
9771 | char *signame = NULL; | |
9772 | if (code == TS_SIGABRT) signame = "ABRT"; | |
9773 | if (code == TS_SIGALRM) signame = "ALRM"; | |
9774 | if (code == TS_SIGFPE) signame = "FPE"; | |
9775 | if (code == TS_SIGHUP) signame = "HUP"; | |
9776 | if (code == TS_SIGILL) signame = "ILL"; | |
9777 | if (code == TS_SIGINT) signame = "INT"; | |
9778 | if (code == TS_SIGKILL) signame = "KILL"; | |
9779 | if (code == TS_SIGPIPE) signame = "PIPE"; | |
9780 | if (code == TS_SIGQUIT) signame = "QUIT"; | |
9781 | if (code == TS_SIGSEGV) signame = "SEGV"; | |
9782 | if (code == TS_SIGTERM) signame = "TERM"; | |
9783 | if (code == TS_SIGUSR1) signame = "USR1"; | |
9784 | if (code == TS_SIGUSR2) signame = "USR2"; | |
9785 | /* The SSH-2 protocol does in principle support arbitrary named | |
9786 | * signals, including signame@domain, but we don't support those. */ | |
9787 | if (signame) { | |
9788 | /* It's a signal. */ | |
9789 | if (ssh->version == 2 && ssh->mainchan) { | |
9790 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); | |
9791 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); | |
9792 | ssh2_pkt_addstring(pktout, "signal"); | |
9793 | ssh2_pkt_addbool(pktout, 0); | |
9794 | ssh2_pkt_addstring(pktout, signame); | |
9795 | ssh2_pkt_send(ssh, pktout); | |
9796 | logeventf(ssh, "Sent signal SIG%s", signame); | |
9797 | } | |
9798 | } else { | |
9799 | /* Never heard of it. Do nothing */ | |
9800 | } | |
9801 | } | |
9802 | } | |
9803 | ||
9804 | void *new_sock_channel(void *handle, Socket s) | |
9805 | { | |
9806 | Ssh ssh = (Ssh) handle; | |
9807 | struct ssh_channel *c; | |
9808 | c = snew(struct ssh_channel); | |
9809 | ||
9810 | c->ssh = ssh; | |
9811 | ssh2_channel_init(c); | |
9812 | c->halfopen = TRUE; | |
9813 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ | |
9814 | c->u.pfd.s = s; | |
9815 | add234(ssh->channels, c); | |
9816 | return c; | |
9817 | } | |
9818 | ||
9819 | /* | |
9820 | * This is called when stdout/stderr (the entity to which | |
9821 | * from_backend sends data) manages to clear some backlog. | |
9822 | */ | |
9823 | static void ssh_unthrottle(void *handle, int bufsize) | |
9824 | { | |
9825 | Ssh ssh = (Ssh) handle; | |
9826 | int buflimit; | |
9827 | ||
9828 | if (ssh->version == 1) { | |
9829 | if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { | |
9830 | ssh->v1_stdout_throttling = 0; | |
9831 | ssh_throttle_conn(ssh, -1); | |
9832 | } | |
9833 | } else { | |
9834 | if (ssh->mainchan) { | |
9835 | ssh2_set_window(ssh->mainchan, | |
9836 | bufsize < ssh->mainchan->v.v2.locmaxwin ? | |
9837 | ssh->mainchan->v.v2.locmaxwin - bufsize : 0); | |
9838 | if (ssh->cfg.ssh_simple) | |
9839 | buflimit = 0; | |
9840 | else | |
9841 | buflimit = ssh->mainchan->v.v2.locmaxwin; | |
9842 | if (ssh->mainchan->throttling_conn && bufsize <= buflimit) { | |
9843 | ssh->mainchan->throttling_conn = 0; | |
9844 | ssh_throttle_conn(ssh, -1); | |
9845 | } | |
9846 | } | |
9847 | } | |
9848 | } | |
9849 | ||
9850 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) | |
9851 | { | |
9852 | struct ssh_channel *c = (struct ssh_channel *)channel; | |
9853 | Ssh ssh = c->ssh; | |
9854 | struct Packet *pktout; | |
9855 | ||
9856 | logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port); | |
9857 | ||
9858 | if (ssh->version == 1) { | |
9859 | send_packet(ssh, SSH1_MSG_PORT_OPEN, | |
9860 | PKT_INT, c->localid, | |
9861 | PKT_STR, hostname, | |
9862 | PKT_INT, port, | |
9863 | /* PKT_STR, <org:orgport>, */ | |
9864 | PKT_END); | |
9865 | } else { | |
9866 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); | |
9867 | ssh2_pkt_addstring(pktout, "direct-tcpip"); | |
9868 | ssh2_pkt_adduint32(pktout, c->localid); | |
9869 | ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ | |
9870 | ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ | |
9871 | ssh2_pkt_addstring(pktout, hostname); | |
9872 | ssh2_pkt_adduint32(pktout, port); | |
9873 | /* | |
9874 | * We make up values for the originator data; partly it's | |
9875 | * too much hassle to keep track, and partly I'm not | |
9876 | * convinced the server should be told details like that | |
9877 | * about my local network configuration. | |
9878 | * The "originator IP address" is syntactically a numeric | |
9879 | * IP address, and some servers (e.g., Tectia) get upset | |
9880 | * if it doesn't match this syntax. | |
9881 | */ | |
9882 | ssh2_pkt_addstring(pktout, "0.0.0.0"); | |
9883 | ssh2_pkt_adduint32(pktout, 0); | |
9884 | ssh2_pkt_send(ssh, pktout); | |
9885 | } | |
9886 | } | |
9887 | ||
9888 | static int ssh_connected(void *handle) | |
9889 | { | |
9890 | Ssh ssh = (Ssh) handle; | |
9891 | return ssh->s != NULL; | |
9892 | } | |
9893 | ||
9894 | static int ssh_sendok(void *handle) | |
9895 | { | |
9896 | Ssh ssh = (Ssh) handle; | |
9897 | return ssh->send_ok; | |
9898 | } | |
9899 | ||
9900 | static int ssh_ldisc(void *handle, int option) | |
9901 | { | |
9902 | Ssh ssh = (Ssh) handle; | |
9903 | if (option == LD_ECHO) | |
9904 | return ssh->echoing; | |
9905 | if (option == LD_EDIT) | |
9906 | return ssh->editing; | |
9907 | return FALSE; | |
9908 | } | |
9909 | ||
9910 | static void ssh_provide_ldisc(void *handle, void *ldisc) | |
9911 | { | |
9912 | Ssh ssh = (Ssh) handle; | |
9913 | ssh->ldisc = ldisc; | |
9914 | } | |
9915 | ||
9916 | static void ssh_provide_logctx(void *handle, void *logctx) | |
9917 | { | |
9918 | Ssh ssh = (Ssh) handle; | |
9919 | ssh->logctx = logctx; | |
9920 | } | |
9921 | ||
9922 | static int ssh_return_exitcode(void *handle) | |
9923 | { | |
9924 | Ssh ssh = (Ssh) handle; | |
9925 | if (ssh->s != NULL) | |
9926 | return -1; | |
9927 | else | |
9928 | return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX); | |
9929 | } | |
9930 | ||
9931 | /* | |
9932 | * cfg_info for SSH is the currently running version of the | |
9933 | * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.) | |
9934 | */ | |
9935 | static int ssh_cfg_info(void *handle) | |
9936 | { | |
9937 | Ssh ssh = (Ssh) handle; | |
9938 | return ssh->version; | |
9939 | } | |
9940 | ||
9941 | /* | |
9942 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if | |
9943 | * that fails. This variable is the means by which scp.c can reach | |
9944 | * into the SSH code and find out which one it got. | |
9945 | */ | |
9946 | extern int ssh_fallback_cmd(void *handle) | |
9947 | { | |
9948 | Ssh ssh = (Ssh) handle; | |
9949 | return ssh->fallback_cmd; | |
9950 | } | |
9951 | ||
9952 | Backend ssh_backend = { | |
9953 | ssh_init, | |
9954 | ssh_free, | |
9955 | ssh_reconfig, | |
9956 | ssh_send, | |
9957 | ssh_sendbuffer, | |
9958 | ssh_size, | |
9959 | ssh_special, | |
9960 | ssh_get_specials, | |
9961 | ssh_connected, | |
9962 | ssh_return_exitcode, | |
9963 | ssh_sendok, | |
9964 | ssh_ldisc, | |
9965 | ssh_provide_ldisc, | |
9966 | ssh_provide_logctx, | |
9967 | ssh_unthrottle, | |
9968 | ssh_cfg_info, | |
9969 | "ssh", | |
9970 | PROT_SSH, | |
9971 | 22 | |
9972 | }; |